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

Annotations already declare a mutating, idempotent, destructive operation, so the safety profile is covered structurally. The description adds the partial-update contract ('Send only what changes'), usefully implying omitted fields are left alone, but it never explains what destructiveHint actually means here or whether an omitted field resets.

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 short sentences, front-loaded with the action and the partial-update rule; nothing is wasted. The pronoun 'they' is slightly ambiguous (the user), which keeps it from a 5.

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?

No output schema exists, but with 100% schema coverage and annotations covering the mutation profile, the description supplies the one thing not in structured data: the partial-update contract. Minor gaps remain around omitted-field behavior.

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%, and the schema fully documents the 'mix' enum values and the kettlebells weight classes and counts. The description merely names the same fields without adding format or constraint detail, 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 ('Changes') and resource (profile), naming the two updatable fields (mix/endurance, kettlebells). It does not explicitly differentiate itself from the sibling 'my_profile' read tool, so it is clear but not fully sibling-differentiating.

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?

'Send only what changes' gives a partial-update instruction, which is a usage hint, but there is no guidance on when to use this versus 'my_profile' or when not to call it. Usage is implied rather than stated.

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