Your team connected an internal MCP server whose find_symbol_references tool resolves references through re-exports, aliases, and dependency-injection bindings. Its description reads only "Finds references." Session logs show the agent nearly always uses the built-in Grep instead, and so it misses aliased call sites when engineers ask about legacy services. What is the most effective first step?

Answer: C — Expand the tool's description to explain that it resolves aliases, re-exports, and injected bindings, what it returns, and when to prefer it over Grep.

Tool descriptions are the main signal the model uses to choose a tool. Section 6 specifically calls for enhancing MCP tool descriptions so the agent stops preferring built-in tools like Grep over a more capable MCP tool. (a) is too blunt: Grep is still the right tool for string literals and error messages. (b) adds engineering work in a hook to make up for a weak description and wastes a call on every search. (d) is a broad keyword-style instruction that sends the agent to MCP tools even where they don't fit, and it still leaves the agent with no idea what this tool actually does.