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

Annotations already carry the safety profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lower. The description still adds value by disclosing negative scope: it does not check UUID uniqueness and does not resolve referenced resources, which prevents false expectations about what a 'pass' means.

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 sentences and a leading fragment, front-loaded with the core action. It is tight overall, though the opening fragment ('Canonical UUID, optionally filter by version') partially duplicates the following sentence rather than adding new information.

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?

For a simple read-only validator with no output schema, the description covers the action, the version filter, the create-alternative, and the important non-behaviors. It does not mention the boolean return shape, but that is minor for a predicate-style tool whose annotations already establish it is a safe read.

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 100%, so both parameters are already documented with their formats and the 1-8 version range. The description only restates 'optionally filter by version' without adding syntax or default semantics beyond the schema, so the baseline 3 applies.

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?

States a specific verb (verify) and resource (a canonical UUID string), and immediately distinguishes itself from the sibling that creates UUIDs by naming generate-token. An agent can tell it apart from the other is-*-safe validators because the resource (UUID) is explicit.

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 usage context ('Use to verify a UUID string, optionally limiting acceptance to a specific version') and routes the agent to the correct alternative ('To create new UUIDs, use generate-token'). It also states exclusions (no uniqueness check, no resolution), leaving little to inference.

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