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

With no annotations, the description carries the full behavioral burden; it does disclose useful traits — the return fields (slug, params, per-call price in prepaid credits) and the fact that misses are logged so missing APIs get added. It stops short of stating auth needs, result limits, or pagination, which matters for a catalog search tool that returns an unbounded set of matches.

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?

Two sentences, front-loaded with the core purpose, then the return shape and the logging side-effect. No filler or restatement of the name; every clause carries information.

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?

For a one-parameter search tool with no output schema, the description covers the essential contract: what is searched, what comes back (slug, params, price), and the miss-logging behavior. It would be fully complete with a note on result volume or pagination, but it is sufficient for correct invocation.

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% and the single query parameter is fully documented as 'What kind of API you need, in plain words.' The description adds no syntax, format, or keyword guidance beyond the schema, so the baseline 3 is appropriate when the schema does the heavy lifting.

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 (Search) and resource (the apifare catalog of ready-to-call APIs) and enumerates the domain (web search, scraping, weather), so the agent knows exactly what is being queried. It is distinguishable from call_api by implication, but it never names the sibling or explicitly frames this as the discovery step preceding invocation.

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?

The catalog-search framing implies it is used to find an API before calling one via call_api, and the 'every miss is logged' note hints at expected negative-result usage. However, there is no explicit when-to-use, no statement of when not to use it, and no named alternative, so the guidance remains inferred rather than stated.

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