Get activity

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds the substantive value of disclosing exactly what data comes back — metrics, device/location metadata and lap splits — which is important since there is no output schema. It does not mention rate limits, auth prerequisites, or what happens if the activity_id is invalid, keeping it below a 5.

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?

Two compact blocks: what is returned, then the one parameter with its source. Nothing is redundant, and the payload description is front-loaded before the parameter note.

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 must carry the return contract, and it does so at a reasonable level of granularity; with one required parameter, it also explains the ID's origin. Minor gaps remain (no note on units, missing-data behavior, or the download alternative), but nothing an agent needs in order to invoke it correctly is absent.

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%: the single parameter is only labeled 'Activity Id' with no explanation. The description compensates by defining activity_id and specifying where to obtain it from sibling tools, which is precisely the semantics an agent needs. It does not specify the expected type/format beyond the schema, so not a full 5.

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?

'Full detail for one activity' states a specific verb, resource and cardinality, and the enumeration of what's included (summary metrics, device/location metadata, split/lap summaries) makes the scope concrete. This reads clearly as the single-activity deep-dive counterpart to the list-returning garmin_search_activities, so an agent can tell them apart without opening either 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?

The description explicitly routes the agent on how to obtain the required input, naming garmin_search_activities and garmin_get_day as ID sources, which is real usage guidance. It stops short of stating when not to use this tool (e.g., garmin_download_activity for the raw file, garmin_get_activity_workouts for associated workouts), so there are no explicit exclusions.

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