gc_mcp

gc_mcp exposes Grand Central daemon capabilities as MCP tools.

Parameter validation

Every tool rejects unsupported top-level parameters before its callback can contact gc_daemon. MCP returns its standard isError: true tool result; the diagnostic names the rejected parameter and lists the parameters registered for that tool. This makes a misspelled or obsolete option recoverable instead of silently ignoring it.

This boundary does not alter nested payload contracts: a declared map or object parameter continues to accept the nested values its existing schema allows.

Related MCP server: mcp-server

Configuration

Why GH_DEFAULT_REPO does not apply to writes

gh_issue_create, gh_issue_edit and gh_issue_comment require an explicit repo. A write that infers its target from ambient configuration will eventually file into the wrong tracker, and the caller who omitted the argument gets no signal that it happened — the operation succeeds, somewhere else. Reads carry no such consequence, so they may fall back to the environment.

There is deliberately no compiled-in default. A shipped repository name aims every installation's bare calls at whatever tracker the author last worked on.