feet(tools+context): Dynamic tool registration by ioanarm · Pull Request #309 · grafana/mcp-grafana

ioanarm · 2025-10-03T08:20:59Z

Dynamic Toolset Discovery and Loading

Summary

Adds dynamic toolset functionality that allows clients to discover and selectively enable tool categories at runtime, significantly reducing context window usage by only loading tools when needed.

Motivation

MCP tool descriptions can consume substantial context window space. By enabling dynamic discovery, clients only load the tools they actually need, preserving context for more important data.

Implementation

New flag: --dynamic-toolsets enables dynamic toolset mode
Discovery tools: Added grafana_list_toolsets and grafana_enable_toolset meta-tools
Notification support: Sends tools/list_changed notification when toolsets are enabled, triggering client refresh

Integration with --enabled-tools:

No flag --> all toolsets discoverable
--enabled-tools="" --> no toolsets discoverable
--enabled-tools="datasources,dashboards" --> only specified toolsets discoverable

Limitations and client compatibility

Protocol Support:
✅ stdio protocol - Fully supported
✅ SSE (Server-Sent Events) - Fully supported
✅ Streamable HTTP - Fully supported
After pr https://github.com/grafana/mcp-grafana/pull/314/files from @sd2k all protocols are supported.

Client Support
✅ Supported: Cursor, VSCode (support notifications),
❌ Not Supported: Claude Desktop, Claude Code

Known Behavior

Slight delay expected: There may be a few seconds of delay between calling grafana_enable_toolset and the tools becoming available in the client, as the client needs to receive and process the tools/list_changed notification.

Note: This is opt-in via the --dynamic-toolsets flag. Existing static tool registration remains the default behavior.

How it works with Cursor.

Currently Sonnet 4.5 model selected - 1m tokens available for this conversation

Normal behavior all tools available:

At the beginning 13.9% of context used
How many tools are available 14.1%
List my prometheus datasources 14.8%

Dynamic tool discovery enabled with all tools discoverable.

At the beginning 5.5% of context used
List available toolsets - 5.9%
Enable Datasource toolset
List Datasources 7%

gerboland

nit: please update the README to reflect the new CLI flag & behaviour.

ioanarm · 2025-10-06T12:14:56Z

Added a comment about supported protocols.
Thanks @gerboland for trying it.

gerboland · 2025-10-06T13:19:25Z

My Cursor is still struggling with this, while it can enable the datasource toolset, it fails to recognise the tools as callable.

I have verified the notifications/tools/list_changed event is being sent by mcp-grafana on toolset change:

So I think Cursor is the problem for me. Should it update the list of tools in its MCP settings UI on the notifications/tools/list_changed event?

sd2k

Love the idea!

sd2k · 2025-10-06T14:26:32Z

dynamic_tools.go

+// ToolsetInfo provides information about a toolset
+type ToolsetInfo struct {
+	Name        string `json:"name" jsonschema:"required,description=The name of the toolset"`
+	Description string `json:"description" jsonschema:"description=Description of what the toolset provides"`
+	Enabled     bool   `json:"enabled" jsonschema:"description=Whether the toolset is currently enabled"`
+}


Do you think it would be worth including ToolNames []string here, as a more concrete hint of what tools this contains?

sd2k · 2025-10-06T14:27:18Z

README.md

+- ✅ **stdio protocol** - Fully supported
+- ❌ **SSE (Server-Sent Events)** - Not yet supported
+- ❌ **Streamable HTTP** - Not yet supported


Huh, is this because notifications aren't as well supported over streamable HTTP?

This is now fixed. After rebasing on top of your PR. https://github.com/grafana/mcp-grafana/pull/314/files 🥳

ioanarm · 2025-11-02T23:07:13Z

So I think Cursor is the problem for me. Should it update the list of tools in its MCP settings UI on the notifications/tools/list_changed event?

Yeah it should update on the UI as well. The moment you ask more tools to be enabled and the tool is called, the new tools should appear on the UI.
Can you try with SSE? This works now.

sd2k

Looks cool! Would love to see it in, think we need to fix conflicts and lints/tests but otherwise LGTM

sd2k · 2025-12-15T19:37:07Z

README.md

+| `grafana_list_toolsets`           | Meta        | List available toolsets for [dynamic discovery](#dynamic-toolset-discovery) | None (meta-tool)                        | N/A                                                 |
+| `grafana_enable_toolset`          | Meta        | Enable a specific toolset [dynamically](#dynamic-toolset-discovery) | None (meta-tool)                        | N/A                                                 |


nit: let's keep this table aligned

sd2k · 2025-12-15T19:37:51Z

README.md

+
+**Integration with `--enabled-tools`:**
+- No flag → all toolsets are discoverable
+- `--enabled-tools=""` → no toolsets are discoverable


Is this ever likely to be useful? I wonder if we should just error in this case 🤷

sd2k · 2025-12-15T19:40:14Z

README.md

+
+**How it works:**
+1. Start the server with `--dynamic-toolsets` flag
+2. Use `grafana_list_toolsets` to discover available toolset categories


This list conflates things that the user does (start the server) with things that the LLM does (use those tools); we should make it clear that the user doesn't have to actually do those things, and it's the LLM doing it instead.

sd2k · 2025-12-15T19:42:25Z

README.md

+| `grafana_list_toolsets`           | Meta        | List available toolsets for [dynamic discovery](#dynamic-toolset-discovery) | None (meta-tool)                        | N/A                                                 |
+| `grafana_enable_toolset`          | Meta        | Enable a specific toolset [dynamically](#dynamic-toolset-discovery) | None (meta-tool)                        | N/A                                                 |


GitHub's dynamic tool discovery has 3 tools (enable_toolset, list_available_toolsets, get_toolset_tools) - did you experiment with this instead? I guess get_toolset_tools returns some more detailed info about the tools vs just the name (which we provide in the toolset list).

Either way we can iterate on that, not a blocker!

I haven't no. I don't remember this being a thing when I raised this PR.
I can have a look if we push this but I would do it separately mainly because I need to put time again into that! 😏

README.md

Co-authored-by: Ben Sully <ben.sully@grafana.com>

github-actions · 2026-02-06T13:37:28Z

MCP Token Analysis

✅ Passed

Metric	Value
Baseline	13967 tokens
Current	13967 tokens
Change	+0 (+0.0%)

sd2k

Very much like this!

sd2k · 2026-02-09T15:58:04Z

cmd/mcp-grafana/main.go

+	// Define all available toolsets
+	allToolsets := []struct {
+		name        string
+		description string
+		toolNames   []string
+		addFunc     func(*server.MCPServer)
+	}{
+		{"search", "Tools for searching dashboards, folders, and other Grafana resources", []string{"search_dashboards", "search_folders"}, tools.AddSearchTools},
+		{"datasource", "Tools for listing and fetching datasource details", []string{"list_datasources", "get_datasource_by_uid", "get_datasource_by_name"}, tools.AddDatasourceTools},
+		{"incident", "Tools for managing Grafana Incident (create, update, search incidents)", []string{"list_incidents", "create_incident", "add_activity_to_incident", "get_incident"}, func(mcp *server.MCPServer) { tools.AddIncidentTools(mcp, enableWriteTools) }},
+		{"prometheus", "Tools for querying Prometheus metrics and metadata", []string{"list_prometheus_metric_metadata", "query_prometheus", "list_prometheus_metric_names", "list_prometheus_label_names", "list_prometheus_label_values"}, tools.AddPrometheusTools},
+		{"loki", "Tools for querying Loki logs and labels", []string{"list_loki_label_names", "list_loki_label_values", "query_loki_stats", "query_loki_logs"}, tools.AddLokiTools},
+		{"alerting", "Tools for managing alert rules and notification contact points", []string{"list_alert_rules", "get_alert_rule_by_uid", "list_contact_points", "create_alert_rule", "update_alert_rule", "delete_alert_rule"}, func(mcp *server.MCPServer) { tools.AddAlertingTools(mcp, enableWriteTools) }},
+		{"dashboard", "Tools for managing Grafana dashboards (get, update, extract queries)", []string{"get_dashboard_by_uid", "update_dashboard", "get_dashboard_panel_queries", "get_dashboard_property", "get_dashboard_summary"}, func(mcp *server.MCPServer) { tools.AddDashboardTools(mcp, enableWriteTools) }},
+		{"folder", "Tools for managing Grafana folders", []string{"create_folder"}, func(mcp *server.MCPServer) { tools.AddFolderTools(mcp, enableWriteTools) }},
+		{"oncall", "Tools for managing OnCall schedules, shifts, teams, and users", []string{"list_oncall_schedules", "get_oncall_shift", "get_current_oncall_users", "list_oncall_teams", "list_oncall_users", "list_alert_groups", "get_alert_group"}, tools.AddOnCallTools},
+		{"asserts", "Tools for Grafana Asserts cloud functionality", []string{"get_assertions"}, tools.AddAssertsTools},
+		{"sift", "Tools for Sift investigations (analyze logs/traces, find errors, detect slow requests)", []string{"get_sift_investigation", "get_sift_analysis", "list_sift_investigations", "find_error_pattern_logs", "find_slow_requests"}, func(mcp *server.MCPServer) { tools.AddSiftTools(mcp, enableWriteTools) }},
+		{"admin", "Tools for administrative tasks (list teams, manage users)", []string{"list_teams", "list_users_by_org"}, tools.AddAdminTools},
+		{"pyroscope", "Tools for profiling applications with Pyroscope", []string{"list_pyroscope_label_names", "list_pyroscope_label_values", "list_pyroscope_profile_types", "fetch_pyroscope_profile"}, tools.AddPyroscopeTools},
+		{"navigation", "Tools for generating deeplink URLs to Grafana resources", []string{"generate_deeplink"}, tools.AddNavigationTools},
+		{"annotations", "Tools for managing annotations", []string{"get_annotations", "create_annotation", "create_graphite_annotation", "update_annotation", "patch_annotation", "get_annotation_tags"}, func(mcp *server.MCPServer) { tools.AddAnnotationTools(mcp, enableWriteTools) }},
+		{"rendering", "Tools for rendering dashboard panels as images", []string{"get_panel_image"}, tools.AddRenderingTools},
+	}


This is gonna get out of date very quickly 😅 can we think of a better way of constructing this slice automatically?

sd2k · 2026-02-09T15:58:28Z

cmd/mcp-grafana/main.go

+- search: Search dashboards, folders, and resources
+- datasource: Manage datasources
+- prometheus: Query Prometheus metrics
+- loki: Query Loki logs
+- dashboard: Manage dashboards
+- folder: Manage folders
+- incident: Manage incidents
+- alerting: Manage alerts
+- oncall: Manage OnCall schedules
+- asserts: Grafana Asserts functionality
+- sift: Sift investigations
+- admin: Administrative tasks
+- pyroscope: Application profiling
+- navigation: Generate deeplinks
+- proxied: Access tools from external MCP servers (like Tempo) through dynamic discovery


likewise I think this will get out of date quickly.

sd2k · 2026-02-09T16:06:47Z

README.md

+- ✅ **Cursor** - Fully supported (supports notifications via stdio, SSE, and streamable-http)
+- ✅ **VS Code** - Fully supported (supports notifications via stdio, SSE, and streamable-http)
+- ❌ **Claude Desktop** - Not yet supported (no notification support, but open issues exist)
+- ❌ **Claude Code** - Not yet supported (no notification support, but open issues exist)


Any chance these have been updated since we last checked?

ioanarm requested a review from a team as a code owner October 3, 2025 08:20

gerboland reviewed Oct 6, 2025

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sd2k self-requested a review October 6, 2025 10:57

sd2k reviewed Oct 6, 2025

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ioanarm force-pushed the dynamic-tool-reg branch from 3744eaa to 88579d6 Compare November 2, 2025 22:59

ioanarm force-pushed the dynamic-tool-reg branch from 835e637 to f57223e Compare November 13, 2025 08:33

ioanarm force-pushed the dynamic-tool-reg branch from f57223e to b28d052 Compare November 21, 2025 07:23

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ioanarm force-pushed the dynamic-tool-reg branch from b28d052 to 73f99c7 Compare January 21, 2026 17:35

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ioanarm added 9 commits February 2, 2026 09:48

add test file

1202786

remove some comments

75b4451

update README

2583806

add dynamic tool functionality

7b47aa1

enable tools and dynamic tools enablement

dbe7dce

add a comment on where the dynamic tool capability is triggered

e8fd8a2

rebase

8cc4e4c

weird rebase

b2b23bb

add toolNames list

f9bef8d

ioanarm and others added 5 commits February 2, 2026 09:48

lint

34d1563

Update README.md

6941615

Co-authored-by: Ben Sully <ben.sully@grafana.com>

review comments

acc7003

dynamic toolsets parsing and error handling

ea613fa

revert enabling admin by default

610b045

ioanarm force-pushed the dynamic-tool-reg branch from d52bd80 to 610b045 Compare February 2, 2026 07:48

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attemp to fix teardown error

823ab44

sd2k changed the title ~~feet(tools+context): Dynamic tool reg~~ feet(tools+context): Dynamic tool registration Feb 9, 2026

sd2k reviewed Feb 9, 2026

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		\| `grafana_list_toolsets` \| Meta \| List available toolsets for [dynamic discovery](#dynamic-toolset-discovery) \| None (meta-tool) \| N/A \|
		\| `grafana_enable_toolset` \| Meta \| Enable a specific toolset [dynamically](#dynamic-toolset-discovery) \| None (meta-tool) \| N/A \|

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ioanarm commented Oct 3, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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Dynamic Toolset Discovery and Loading

Summary

Motivation

Implementation

Integration with --enabled-tools:

Limitations and client compatibility

Known Behavior

How it works with Cursor.

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MCP Token Analysis

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