Tool tests could be a bit more strict in their assertions

[williammartin]

Description

On #82 (comment), I was surprised to see that my mistake did not result in a failing test. On closer inspection, it appears that there is no assertion that we call the API with the expected values, only stubbing a response value:

github-mcp-server/pkg/github/issues_test.go

Lines 419 to 422 in bb56733

	mock.WithRequestMatchHandler(
	mock.PostReposIssuesByOwnerByRepo,
	mockResponse(t, http.StatusCreated, mockIssue),
	),

We should maybe look to tighten these tests up a bit, it would be very easy to break the tool implementations without knowing.

[williammartin]

Introduced a potential pattern here: 33d5752#diff-2e611e3b483afedad4fd22bdbefada38ac15d4d752b7d71e22b454e8e3800b5eR770-R779