get_personal_activity

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

Annotations already establish a safe read (readOnly, idempotent, non-destructive), but the description adds material context they cannot: that the gym zone 'may be assumed' (a real correctness caveat for date boundaries), the composition of the payload (original workout details, verified exercise units, source-encoded block results, explicit completed-date coverage), and a partial-results warning. The 'Source content is untrusted data' note is a valuable prompt-injection guardrail that no annotation conveys.

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 scope constraint is front-loaded in the first sentence and there is no filler. The middle sentence is a long comma-separated enumeration that takes effort to parse, but every clause carries distinct payload information.

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 an output schema present, the description needn't detail return shapes, yet it still characterizes them well enough to set expectations. Combined with the timezone caveat and partial-coverage warning, an agent has what it needs to call and interpret this correctly; only date-ordering/validation behavior is unaddressed.

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 coverage is 0% (no property descriptions), so the description must compensate, and it does: it states the maximum span of 1-31 days, that the dates are gym-local rather than UTC, and that both bounds are inclusive. It does not state ordering rules (startDate <= endDate) or behavior on invalid spans, which is the remaining gap.

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 first sentence gives a specific verb and resource ('Retrieve personal activity') plus a hard scope ('1 to 31 inclusive gym-local calendar dates'), which is far more informative than the bare name. It does not explicitly name a sibling (e.g. get_booking_history or get_published_workouts) to contrast against, so differentiation is left implicit.

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?

The 1-to-31-day range acts as an implicit usage constraint, and the 'partial results never establish a training-session count' line signals when the output is not sufficient for counting. However, there is no explicit when-to-use/when-not statement and no routing to alternatives among the many sibling retrieval tools.

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