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

Annotations only declare the safety profile (not read-only, not destructive, closed-world); the description adds genuinely new behavior: endpoint and field selection is made by the service, a human reviews the build, and the user is emailed at each step — signalling an asynchronous, non-immediate workflow. It omits cost implications, turnaround expectations, and how to poll the result, 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 tight sentence that front-loads the purpose, then the input mode, then the workflow outcome. No filler, no repetition of schema detail beyond what is needed for orientation.

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?

With no output schema, the description correctly explains what happens after the call — automated design, human review, email notifications — which is the key missing piece an agent needs. It could go further by pointing at get_api_request/list_api_requests for retrieving the resulting build, but it is otherwise sufficient for a 2-parameter request 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 description coverage is 100%, so both parameters are already documented, and the description largely restates the same page-vs-domain mapping (including the paid-plan restriction already in the schema). Baseline 3 applies since it adds little meaning beyond the structured fields.

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 — request that API.SH build endpoints for a public site — and scopes it to sites 'not in the catalog', which cleanly separates it from search_apis (finding catalogued APIs) and call_api (invoking one). An agent can tell what this does 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?

The 'isn't in the catalog' clause functions as an explicit when-to-use condition, and the kind 'page' vs 'site' split gives further routing guidance. It stops short of naming the alternative tool (e.g. search_apis first) or stating when not to use it, so it lands just below the top.

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