Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already cover read-only, open-world, idempotent, non-destructive, but the description adds real behavior: rules are read live from the list's files and cached 6 h, public reads only with nothing opened or posted, 422/503 failure semantics, 1-6 s latency (slower on cold list read), USD 0.005 price, a 10-call/day free tier, and an untrusted-data caution. This is well beyond what the annotations declare.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Purpose is front-loaded, then sibling routing, then behavior, cost, and a docs link, so the structure serves the reader. It is dense and long, and the price/free-tier lines could be trimmed for a tool an agent selects on purpose, but nearly every sentence carries selection or invocation value.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

An output schema exists so return values need no explanation, yet the description still summarizes what comes back (per-rule pass/fail with README line and PR title). Errors, timing, cost, caching, and a prompt-injection caution are all covered, leaving nothing material an agent needs before calling.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the baseline is 3, but the description goes further by grouping the inputs by list variant ('repo, list, optional description, category, tags; remote list also endpoint, homepage, auth, connector'), which clarifies when each optional group applies. It does not add format or syntax detail beyond the schema, so it stays short of a 5.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('Check an MCP server repo against a punkpeye awesome list's rules before opening a PR') and explicitly names the two nearest siblings, check_mcp_server and scan_agent_package, with what each does instead. An agent can tell this apart from every sibling without opening a schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives the decision context up front ('before opening a PR') and routes to alternatives with their conditions ('To see whether the server answers use check_mcp_server; to scan its code use scan_agent_package'). No inference required to pick the right tool.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.