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

No annotations present, so description bears full responsibility. It discloses constraints: both specs must be valid, self-contained OpenAPI, no external $ref resolution. It does not explicitly state the tool is read-only, but that is implied. Could mention output format but acceptable.

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?

Three concise sentences that efficiently convey purpose, usage, constraints, and alternatives. No unnecessary words.

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?

Covers all essential aspects: purpose, usage, constraints, and sibling differentiation. Lacks output description, but given the tool's simplicity and no output schema, it is mostly complete.

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%, baseline 3. Description adds format clarification ('as YAML or JSON') and constraints (no external $refs) that augment the schema's property descriptions, justifying a higher score.

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 shows 'structural diff between two OpenAPI specifications' and specifies 'what was added, removed, or modified'. It distinguishes from siblings by explicitly naming and contrasting with oasdiff_breaking_changes and oasdiff_changelog.

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?

Provides explicit guidance: 'Use this when you want the raw structural changes rather than a backward-compatibility verdict' and directs to sibling tools for other purposes. No ambiguity.

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