garmin_readiness

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 genuinely useful context beyond that: an approximate request budget of ~3 Garmin calls per day, which matters for an external API with likely quota constraints. It doesn't discuss latency or failure modes, so not 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?

Three tight sentences: metrics first, use cases second, cost caveat last. Every sentence carries distinct information and the most decision-relevant content is front-loaded.

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 only one optional parameter at full schema coverage, an output schema already defining return values, and annotations covering the read-only nature, there is nothing an agent needs to call this correctly that 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?

The single parameter has 100% schema coverage, including its default of 3 and range of 1-30, so the schema carries the semantics. The description says nothing about the days window or how it affects returned metrics, so it adds no meaning beyond the schema — baseline 3 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 names the specific resource and enumerates the metric families returned: training readiness, recovery time, HRV vs baseline, training status and load, VO2max, endurance and hill scores. That precision distinguishes it from siblings like garmin_sleep or garmin_body_metrics without the agent needing to open any 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?

It gives explicit trigger questions ('am I recovered?', 'should I go hard today?') that map directly to intent, which is strong when-to-use guidance. It stops short of naming an alternative sibling or stating when not to use it, so it falls just short of the top band.

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