Most recent activity

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

Annotations already declare readOnlyHint=true and openWorldHint=true. The description adds no behavioral context beyond a restatement of the name—no mention of data format, limitations, or any quirk. Since it adds zero value over annotations, it scores at the floor.

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 description is extremely concise—a single short phrase—but it under-delivers on content. While there is no word waste, the phrase is so generic that it fails to structure any meaningful information. It is not a case of efficient brevity but rather of under-specification.

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?

Although the tool has an output schema and annotations cover read-only/open-world, the description says almost nothing about the scope of the returned data. It does not clarify whether this returns a full activity object or a summary, nor does it hint at any filters. For a simple tool, this may be marginally acceptable, but it remains too vague to be considered complete.

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?

The tool takes zero parameters, so the baseline for this dimension is 4 per the rubric. There is nothing that the description could add to parameter semantics; the schema already covers everything (100% coverage). The absence of parameter info is appropriate.

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 'The most recently recorded activity' is a near-tautology of the tool name 'garmin_last_activity'. It does not specify a distinct verb, resource scope, or differentiate among siblings like 'garmin_activity' or 'garmin_activities'. An agent cannot infer what makes this tool unique beyond the name.

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?

No guidance is provided on when to use this tool versus alternatives such as 'garmin_activities' (list all) or 'garmin_activity' (a specific activity). There is no mention of context, exclusions, or preferred scenarios.

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