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

Annotations already carry readOnlyHint=true and idempotentHint=true, so the safety profile is covered. The description adds genuinely new behavioral context: output is 'dereferenced from the OpenAPI definition (the source of truth)', informing the agent that $ref pointers are resolved, and that results come as 'structured JSON plus a markdown rendering'. No contradiction with annotations; the read behavior is consistent with readOnlyHint.

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 with zero filler. The core purpose is front-loaded, and the second sentence delivers the identification logic. Every clause earns its place; no redundant restatement of the title or annotations.

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 an output schema present, the return structure is documented externally, so the description need not re-explain it. It covers the dereferencing behavior and the selection logic. The only minor gap is error behavior when an endpoint cannot be found, which is acceptable given the readOnly/idempotent annotations and available output schema.

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 all three parameters (path, method, operationId) are already documented. The description adds value beyond the schema by explaining the parameter relationship: the endpoint can be identified by operationId OR by method+path, which clarifies that the parameters are alternative selectors rather than jointly required — essential given 0 required parameters.

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?

The description states a specific verb and resource: it returns 'the exact request and response shape of one endpoint'. It clearly differentiates from siblings — list_endpoints ('one endpoint' vs. listing) and search — and specifies both the output format ('structured JSON plus a markdown rendering') and the identification keys (operationId or method+path). An agent can distinguish this from fetch/list_endpoints/search without inspecting schemas.

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 context is clear: use this tool to retrieve the dereferenced shape of a single endpoint, and the description gives concrete identification guidance ('Identify it by operationId, or by method and path'). It does not name sibling alternatives or explicit when-not scenarios, but given siblings like list_endpoints and search, the singular-scope wording makes the intended usage unambiguous.

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