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

With no annotations, the description carries the disclosure burden and does well: it is evidently a read-only reference fetch and it enumerates the return payload, including the per-call token cost, which is non-obvious operational context. It does not address rate limits, auth, or error behavior for an unknown slug, which keeps it from 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?

One dense sentence describing the payload followed by a short routing instruction — front-loaded, no filler, and every clause adds information an agent would otherwise have to discover by calling the tool.

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, so the description compensates by fully enumerating the response contents, and the single required parameter is already documented in the schema. For a one-parameter read tool there is nothing material an agent needs before calling it.

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 the baseline is 3, and the description adds genuine value beyond the schema by telling the agent to source the slug from search_apis rather than constructing it. The schema already supplies format examples ('sanctions', 'barcode-lookup'), so no further parameter detail is needed.

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+resource (full reference for one API) and enumerates exactly what is returned: endpoints, methods, paths, parameters with examples, request body, example response, and token cost. This clearly separates it from call_api (invoke) and search_apis (discover).

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?

"Use the slug from search_apis" gives explicit workflow guidance on where the required argument comes from and establishes the search-then-inspect sequence. It stops short of stating when not to use this versus call_api, but the context is clear enough to route correctly.

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