[WIP] Update test coverage for tools package

[ghost]

What I did

• Test coverage needs to be improved. CONTRIBUTING.md updated with Testing section - which contains commands for quickly understanding current coverage.
• Increased coverage for tools package to: 58.9% from 36.0% (Note this is only for unit, integration coverage is higher)
• Previously we had a single tools_test.go for the tools package. Switching to a model where we have separate test files for each like: call_test.go and enable_test.go
• Note this PR is dependent on Switch to modelcontextprotocol/go-sdk #77 which is currently failing CI checks. Will continue to update with additional coverage.

Related issue

• Currently unit-test coverage for tools is: 36.0% of statements. See screenshot below for file coverage breakdown:

(not mandatory) A picture of a cute animal, if possible in relation to what you did
🐞

[ghost]

Closing this - will re-open with additional coverage after the updated Go framework PR's are merged