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

Annotations already cover safety (readOnly, idempotent, non-destructive, open world), so the description rightly spends its budget on ranking semantics: pass the user's phrasing through, partial-name matching, compact rows, and the meaning of an empty result. It stops short of describing scoring/freshness or pagination beyond the limit param, so it is strong but not exhaustive.

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?

Front-loaded purpose, then trigger condition, then a compact example block, then return/next-step note. Every sentence earns its place and the examples are the cheapest possible way to convey query construction.

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?

No output schema exists, yet the description tells the agent what comes back (compact rows), what to do next (get_benchmark), and how to handle the null case. Nothing needed to call this correctly is missing.

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 100%, so baseline is 3. The description goes beyond it by explaining that query should be verbatim user phrasing where provider names, chain names and goals all match, which is genuine guidance on how to construct the argument rather than restating the schema.

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: 'Ranks the benchmark catalogue against a question in the user's own words and returns the best few matches.' This clearly separates it from siblings like list_benchmarks (enumerate) and get_benchmark (fetch one full ranking).

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?

Explicit when-to-use trigger ('when somebody asks which provider, chain or service is fastest, cheapest, most reliable or best'), plus three worked examples mapping natural questions to calls, plus the routing instruction to open a result with get_benchmark and the empty-result fallback behavior.

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