Training log

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

Annotations already declare readOnly, idempotent, non-destructive and open-world, so the safety profile is covered. The description adds genuinely new context: that Garmin's own field names and units are used (e.g. power curve as maxAvgPower_<seconds>, splits as fastestSplit_<metres>), which an agent cannot infer from annotations or schema.

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?

Front-loaded with what the tool returns, then the field inventory, then the range cap. The field enumeration is long but earns its place because there is no output schema; only minor tightening is possible.

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 correctly compensates by naming the returned fields and their units, which is what an agent needs to interpret results. The missing piece is how this differs from list_activities/get_activity, which matters given six-plus sibling activity tools.

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 sport and the date bounds are already documented, including the inclusive end_date default. The description adds only the 366-day span limit, which is relevant context but does not deepen parameter meaning beyond the schema baseline.

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 states a specific resource (every activity in a period) plus the exact field set returned under Garmin naming conventions, which is far more concrete than a restatement of the name. It does not, however, distinguish itself from siblings like list_activities or get_activity, leaving ambiguity about which tool returns what.

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?

There is no guidance on when to use this versus list_activities or get_activity, no mention of prerequisites or typical query patterns. The only usage constraint given is the 366-day-per-call cap, which is a limit rather than a selection rule.

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