get_activities

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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds genuine context beyond that: swims return pace per 100 m, pool length, SWOLF and stroke rate instead of pace per km, plus the 'recent' ordering implication and the end_date-relative-to-today behavior. What it doesn't disclose is whether 50 is a hard ceiling, what happens with a very wide date range, or anything about ordering/tie-breaking.

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 purpose sentence, then the swim exception, then a compact Args block. Every line carries information the schema lacks; nothing is repeated from annotations or the JSON 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 an output schema present, there is no obligation to describe return fields, and the args are fully covered. The remaining gap is pagination: for a listing tool capped at 50 there is no statement about how to page past the limit or whether ordering is newest-first, which matters for a tool returning 'recent' items.

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 carries the full burden and does so: limit range (1-50) with default 10, both dates as YYYY-MM-DD, and the non-obvious conditional default that end_date becomes today when start_date is supplied. That conditional behavior is not derivable from the schema's anyOf/default:null at all.

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 (list) plus the resource (recent runs, rides, swims, workouts) and the fields returned (distance, duration, pace, HR zones), and notes the swim-specific variant. It does not explicitly distinguish itself from get_activity_details or list_workouts, so the agent must infer that this is the activity feed rather than planned workouts or a single-activity drill-down.

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?

Usage is implied rather than stated: the word 'recent' plus the limit/date-range args signal this is the default feed query, but there is no explicit 'use this when...' or 'for per-activity detail use get_activity_details' routing. An agent can infer usage from the sibling list but the description does no work to route it.

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