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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds real behavioral context beyond that: rows carry a `source` discriminator (profile | lab | field-test | estimate | self-report) and the profile is overwritten in place, which explains why history is the only way to see movement.

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?

Dense and front-loaded: the core purpose leads, then the contrast with the profile, then the source caveat. It is somewhat long-winded with em-dash chains, but each sentence carries usable information rather than filler.

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?

There is no output schema, so the description partially compensates by describing row structure via the `source` field. Pagination is left to the schema's limit parameter. Adequate for a read-only historical query, though return shape could be fuller.

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 to/from/kinds/limit are already documented, including 'newest first' and date patterns. The description adds no syntax or semantics beyond what the schema provides, 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+resource ('the HISTORY of a measured number') and enumerates the exact kinds it covers (FTP, LTHR, weight, ferritin, etc.). It explicitly contrasts itself with the profile, which carries only the CURRENT value, so an agent can tell it apart from get_athlete_profile without opening a schema.

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?

Gives an explicit trigger ('call it when the question is about a trend, not about today'), notes it is 'Deliberately not in the turn snapshot', and warns to say which source is being compared since a lab number and a field estimate are not the same measurement twice. This is unambiguous when/when-not guidance.

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