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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered structurally. The description adds only the transport detail (POST /v1/schema-diff); it says nothing about output shape, how breaking changes are classified, or how the SemVer recommendation is derived. Useful but thin beyond what annotations supply.

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 compact sentences, front-loaded with the purpose and outcome. The parenthetical endpoint adds little decision value for an agent, but nothing is redundant or padded.

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 carries the return-value burden, and it does convey the two deliverables: detected breaking changes and a SemVer bump recommendation. What is missing is mode semantics and error behavior for invalid schema input, which keeps it from a 5.

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 reported at 100%, which sets the baseline at 3 even though the schema's own parameter descriptions are near-tautological (e.g., "Parameter 'mode' (e.g. \"json_schema\")"). The description adds no meaning about valid 'mode' values, the structure of 'before'/'after', or why 'after' is optional — a real gap given the nested objects.

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?

Specific verb and resource plus a stated outcome; only the title-restating opening and absence of explicit differentiation hold it below 5.

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 use case is implied by 'catch breaking changes and recommend SemVer bumps', so an agent can infer this is for schema compatibility review. However, there is no explicit when-to-use statement, no prerequisite (e.g., both schemas must be same-version-family OpenAPI 3.x), and no guidance on when the optional 'after' should be omitted.

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