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

With no annotations, the description carries the full burden and does add meaningful behavior: it is a paid POST, it caps results at 25, it validates against a curated snapshot, and it describes returned fields including a 0-1 relevance score. Missing auth/permission requirements and rate-limit behavior keeps it short of a 5.

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?

Four packed sentences with no filler; the core purpose and return shape lead. The trailing 'Try GET /discover/sample' is a slightly abrupt tack-on but still earns its place as a low-cost alternative.

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?

It compensates for the absent output schema by enumerating returned fields, which is genuinely useful. But with zero annotation coverage and zero parameter coverage, the definition leaves the caller without auth/cost detail and without parameter semantics, which is more than a minor gap for a paid tool.

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 coverage is 0% for all three parameters, yet the description explains none of them. 'q' (the query format), 'max_results' (and its interaction with the stated 25-match cap), and especially 'min_similarity' (the 0-1 threshold) are left entirely undocumented, so the description fails to compensate for the coverage gap.

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 ('Find MCP servers matching a need') plus the ranking mechanism (semantic similarity over a curated snapshot). Clear on its own, but it never distinguishes itself from the sibling discover_mcp_servers, which sounds like a near-identical capability, so an agent cannot confidently pick between them from this text.

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 cost context ('Paid POST') and a fallback ('Try GET /discover/sample'), which is real usage guidance. However it never says when to use this over discover_mcp_servers or any other search-like sibling, and there are no explicit exclusions.

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