Get Activity Types

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 established. The description adds no extra behavioral context (e.g., return format, whether the list is static or user-specific). Given annotations carry the burden, a baseline 3 is appropriate—no contradiction, but no additional value beyond annotations.

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 a single, clear sentence that immediately conveys the purpose. There is zero filler and it is well-structured with the verb leading.

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?

For a read-only, zero-parameter tool with annotations covering safety, the description fully satisfies the informational needs. It specifies exactly what is returned (all activity types) and the source (Garmin Connect). No further context is necessary.

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 has zero parameters, so the description does not need to explain parameter usage. Per the rubric, a 0-parameter tool receives a baseline score of 4. The description adds nothing about parameters, but none are needed.

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 clearly states the tool's function: retrieving all activity types from Garmin Connect. It uses a specific verb ('Get') and resource ('activity types') with a scope qualifier ('all'), distinguishing it from sibling tools that fetch other data types.

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?

Though no explicit usage guidance or alternatives are mentioned, the tool's purpose inherently implies it should be used when a list of valid activity types is needed. Since there are no obvious sibling alternatives for this specific resource, lack of exclusions is acceptable. The context is clear enough.

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