garmin_list_activities

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

Annotations already cover safety (readOnly, idempotent, non-destructive), so the description's added value is in semantics: dates are the account's calendar dates, activity_type is Garmin's key rather than an exercise name, and results must not be turned into inferred fitness conclusions. That last constraint is a genuine behavioral rule an agent could otherwise violate.

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?

Five short sentences, front-loaded with the purpose, then pagination mechanics, then two disambiguation notes and one behavioral constraint. No filler and nothing repeated from the schema.

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 never indicates what a returned activity record contains, so the agent cannot anticipate the response shape. Date-bound inclusivity and the limit cap are also left out, though the pagination termination rule is a helpful substitute for a documented response envelope.

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 0%, so the description has to carry the burden, and it does for four of five parameters: offset/limit for pagination, start_date/end_date as account calendar dates, and activity_type as a Garmin type key with concrete examples. It does not mention the limit ceiling of 50, the defaults, or whether date bounds are inclusive.

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 opens with a specific verb and resource, 'Read a page of Garmin activities,' which makes clear this is a paginated list operation. 'A page of' implicitly distinguishes it from the single-record sibling garmin_get_activity, though the description never names alternatives explicitly.

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?

Pagination usage is spelled out well: use offset/limit and stop when fewer than limit records come back. However, there is no explicit guidance on when to choose this tool over garmin_get_activity or garmin_get_activity_workouts, so the agent must infer the routing from 'a page of' alone.

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