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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=false). The description adds genuine payload context, spelling out the sections returned (profile fields, active workouts with sets/reps/load, last-30-day session count) and the ownership scoping, which is not stated in annotations.

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?

A single sentence with the resource stated first and the payload details following; every clause carries information. It is a long sentence, but not padded or repetitive.

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 usefully enumerates the return contents, which is the main thing an agent needs. What is missing is failure/edge behavior (unknown id, student not owned by the trainer) and whether results are paginated or capped.

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% and the schema itself documents that student_id comes from list_students, so the schema carries the parameter burden. The description only adds the scoping notion that the student belongs to the trainer, without adding format or constraint detail.

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 and resource ('Gets one of the trainer's students') and enumerates the returned payload (profile, workouts, logged sessions). It is distinguishable from list_students by the singular 'one of', but never names or contrasts with the sibling that returns the collection.

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?

Usage is only implied: fetch one student's full detail rather than a list. There is no explicit when-to-use vs list_students, and no prerequisite such as the student having to belong to the authenticated trainer.

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