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

With no annotations, the description carries the full burden. It explicitly discloses that the tool does not mutate artifacts or generate a new profile, which is the key behavioral trait for a validation tool. However, it does not mention what happens on invalid input or whether there are other side effects, leaving some gaps.

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 two sentences, front-loaded with the primary purpose and followed by a concise behavioral disclaimer. Every piece of text adds value with no redundancy or fluff.

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?

Despite having no annotations, the description covers purpose, usage timing, and side-effect boundaries. The output schema covers return values, and the two parameters are effectively explained. For a validation tool with this simplicity, the description is complete enough to guide correct invocation.

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?

The description maps 'USRProf artifact or inline USRProf JSON' to the two parameters: usrprof_artifact_id and usrprof. This compensates for the schema's missing description on usrprof and clarifies the 'or' relationship. Still, it does not explicitly state whether exactly one must be provided or both are allowed, which could be ambiguous given the schema has no required fields.

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 verb 'Validate' and the resource 'USRProf artifact or inline USRProf JSON', and includes the context 'before creating personalized race plans'. This distinguishes it from sibling tools like validate_course_profile and generate_runner_profile.

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?

It gives clear context on when to use ('before creating personalized race plans') and states a when-not boundary ('This does not mutate artifacts or generate a new profile'). However, it does not explicitly name alternative tools for mutation or generation, stopping short of full alternative guidance.

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