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

Annotations already cover readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile needs no repetition. The description contributes non-obvious behavioral facts instead: the audit's focus areas (schemas, examples, operation IDs, discoverability) and a monetary cost of $0.20 per specification, neither of which appears in annotations or schema. No contradiction with annotations is present.

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?

The description is three sentences, each earning its place: what the tool does, when to use it, and the cost. The most decision-relevant information (purpose) is front-loaded before the usage context and pricing. There is no filler, repetition, or schema duplication.

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?

An output schema exists, so return values need not be described. Annotations cover safety, and the description provides usage timing and price. Still, given 0% schema coverage for parameters, the description should fully define both inputs: it identifies `spec` as an OpenAPI document but leaves `baseUrl` undefined and does not state expected string formats (e.g., YAML, JSON, URL-to-spec, or raw content).

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 0%, so the description must compensate. 'Audit an OpenAPI document' clarifies that the required `spec` parameter is an OpenAPI specification, and the price phrasing ('per API specification') reinforces that meaning. However, the optional `baseUrl` parameter is completely unexplained, leaving unclear whether the parameter is a location, a base URL for the API, or a URL to fetch the spec from; this gap is not filled anywhere else.

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 opening sentence uses a specific verb and resource ('Audit an OpenAPI document') and enumerates the specific dimensions checked (schemas, examples, operation IDs, descriptions, payment/auth discoverability). It is clearly distinct from sibling tools like document_validator or website_accessibility_auditor, though it does not explicitly name a sibling alternative.

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 description 'Use before publishing an API to find missing schemas, examples, operation IDs, and agent-facing guidance' gives a clear context and trigger for when to invoke the tool. It does not, however, mention exclusionary conditions or name alternative tools for different scenarios, so it stops short of a 5. The price note also adds an operational precondition.

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