set_activity_perceived_effort

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

Goes well beyond the annotations (readOnlyHint=false, destructiveHint=false, openWorldHint=true) by disclosing Garmin's non-obvious times-ten storage convention, the out-of-range 400 `MEASUREMENT_NOT_VALID` behavior, and a specific read-modify-write hazard (PUTting back the stored start-coordinate pair yields a 400). This is exactly the server-specific behavior an agent cannot infer from 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?

Three dense clauses/ sentences, no filler, and the scaled-value contract is front-loaded before the error and anti-pattern notes. Each sentence carries a distinct, non-redundant behavior.

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 two-parameter mutation tool with no output schema, the description covers the value contract, the clear operation, an observed server rejection, and the read-modify-write pitfall. Nothing needed to invoke it safely against Garmin is missing.

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 50% and the `rpe` property has no schema description, yet the description fully specifies its semantics: integer 1-10 accepted, transmitted as 10-100, and null accepted to clear. The `activityId` parameter is left to the schema's 'Numeric id', so one parameter remains thin, but the critical encoding detail is supplied.

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 precise verb and resource: a partial PUT that sets the activity's perceived effort (RPE). It is immediately distinguishable from siblings like set_activity_feel, set_activity_description, or set_activity_name, which touch different fields of the same activity.

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?

Gives the valid input range (1-10 integer) and the clearing condition (`null` clears it), which is usable guidance. However, it never states when to choose this tool over adjacent siblings such as set_activity_feel, nor any preconditions for the target activity, so the when-to-use dimension is only implied.

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