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

No annotations are provided, so the description carries the full burden. It usefully discloses a behavioral trait annotations would never cover — the $0.005 per call cost — but says nothing about how deterministic the answer is or whether it may return multiple candidates.

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?

One front-loaded sentence plus examples and a cost note, with no filler. The primary purpose leads and every clause earns its place.

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 lookup with no output schema, the description adequately signals that the return value is a status code, and it discloses cost. It could still say whether the result is a single code or a ranked set, which is the one remaining gap.

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% and the single parameter is documented as 'free text describing what went wrong.' The description goes beyond that by supplying worked examples ('the caller is being rate limited', 'upstream returned garbage') that show the expected phrasing, which genuinely helps formulate the input.

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 (Find) and resource (HTTP status code) plus a precise scope qualifier: 'when the code is not known in advance.' That scope clause implicitly separates it from siblings like http_status (code-first lookup), so an agent can route correctly without opening the 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 a clear condition for use ('when the code is not known in advance') and two concrete triggering examples ('rate limited', 'upstream returned garbage'). It stops short of naming the complementary sibling (e.g. http_status) or stating when not to use it, but the context is unambiguous.

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