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

No annotations are provided, so the description carries full burden for behavioral disclosure. It states the tool returns 'breaking and warning-level changes', and notes the limitation about unresolved external $refs. However, it does not describe error behavior for invalid specs or the exact output format. Slightly more detail on the response structure would improve transparency.

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 concise and well-structured. It starts with the core purpose and return type, then provides usage guidance and alternatives, and ends with constraints. Every sentence adds value and there is no redundancy.

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?

Given the complexity of the tool (comparing two OpenAPI specs for breaking changes) and the absence of an output schema, the description covers purpose, return type, usage, sibling distinctions, and input constraints. It does not detail the output format or error handling, but overall it is sufficiently complete for an agent to select and invoke the tool correctly.

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%, with both parameters described as strings. The description adds meaning by specifying they can be YAML or JSON and that they must be valid, self-contained OpenAPI (no external $ref resolution). This significantly adds context beyond the schema.

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 clearly states the tool's purpose: detecting breaking API changes between two OpenAPI specifications. It specifies the verb ('detect'), resource ('breaking API changes'), and scope ('between two OpenAPI specifications'). The description also distinguishes from siblings by naming alternative tools and their use cases.

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?

Explicit usage guidance is provided: 'Use this when the question is whether an API change breaks existing clients.' The description also lists when to use alternatives (oasdiff_changelog, oasdiff_diff, oasdiff_validate). Additionally, it states prerequisites: both specs must be valid, self-contained OpenAPI with no external $ref resolution.

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