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

Beyond the annotations (write, openWorld, non-destructive), the description discloses real behavioral traits: the entry surfaces in the client's progress, a per-call confirmation default that can be disabled, and that a Cotlet API key with app access is required. These add meaningful value not present in the structured fields.

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 opening is front-loaded with the core action, but the first two sentences are near-identical restatements ('Enter body stats for a client on a date, in the client's units' / 'Enters body stats for one client on one date, in the client's units'), wasting space on duplication.

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 write tool with annotations covering the safety profile and no output schema, the description covers the key operational points: side effect on client progress, confirmation behavior, and auth requirements. It is largely complete, though a note on the destination client's existence or units source would make it fully self-sufficient.

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 the three parameters are already documented, setting the baseline at 3. The description adds only the 'in the client's units' note, which clarifies how the stats values are interpreted but does not elaborate on individual parameter formats.

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 uses a specific verb and resource ('Enter body stats for a client on a date') that clearly marks this as the write counterpart to the sibling read tool trainerize_get_body_stats. It does not explicitly name or contrast with that sibling, but the read/write distinction is unambiguous.

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 some operational guidance ('By default you confirm each call; you can switch that off for this tool' and 'confirm with the user before each call'), which is useful context. However, it never states when to use this versus trainerize_get_body_stats or what prerequisites apply to the client existing, so guidance is implied rather than explicit.

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