fix(skills): fix integer parameter parsing through agent skills (#2847)

This PR fixes an issue where integer parameters were incorrectly parsed
as float64 when invoking tools via the CLI.

Co-authored-by: Pavan Krishna Rampalli <pavanrampalli@google.com>

---------

Co-authored-by: Pavan Krishna Rampalli <pavanrampalli@google.com>

Author: helloeve

cmd/internal/invoke/command.go

@@ -18,10 +18,12 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"strings"
 
 	"github.com/googleapis/genai-toolbox/cmd/internal"
 	"github.com/googleapis/genai-toolbox/internal/server"
 	"github.com/googleapis/genai-toolbox/internal/server/resources"
+	"github.com/googleapis/genai-toolbox/internal/util"
 	"github.com/googleapis/genai-toolbox/internal/util/parameters"
 	"github.com/spf13/cobra"
 )
@@ -87,7 +89,7 @@ func runInvoke(cmd *cobra.Command, args []string, opts *internal.ToolboxOptions)
 
 	params := make(map[string]any)
 	if paramsInput != "" {
-		if err := json.Unmarshal([]byte(paramsInput), &params); err != nil {
+		if err := util.DecodeJSON(strings.NewReader(paramsInput), &params); err != nil {
 			errMsg := fmt.Errorf("params must be a valid JSON string: %w", err)
 			opts.Logger.ErrorContext(ctx, errMsg.Error())
 			return errMsg

cmd/internal/invoke/command_test.go

@@ -68,6 +68,15 @@ tools:
       - name: message
         type: string
         description: message to echo
+  int-tool:
+    kind: sqlite-sql
+    source: my-sqlite
+    description: "int tool"
+    statement: "SELECT ? as val"
+    parameters:
+      - name: value
+        type: integer
+        description: int value
 `
 
 	toolsFilePath := filepath.Join(tmpDir, "tools.yaml")
@@ -92,6 +101,11 @@ tools:
 			args: []string{"invoke", "echo-tool", `{"message": "world"}`, "--config", toolsFilePath},
 			want: `"msg": "world"`,
 		},
+		{
+			desc: "success - tool call with integer parameters",
+			args: []string{"invoke", "int-tool", `{"value": 42}`, "--tools-file", toolsFilePath},
+			want: `"val": 42`,
+		},
 		{
 			desc:    "error - tool not found",
 			args:    []string{"invoke", "non-existent", "--config", toolsFilePath},