get_readiness

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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds valuable scope context by listing the bundled metrics (readiness score/factors, training status, acute vs chronic load, four-week load focus, sleep, HRV, body battery, stress, resting heart rate) and noting it subsumes sleep and daily-summary tools; however, it does not discuss data freshness, failure modes, or other operational behavior. The output schema carries the return structure, so a 4 reflects useful added context without full behavioral disclosure.

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 front-loaded with the core decision and then gives alternatives and parameter details. It is slightly dense in the long run-on sentence listing all included metrics, but every sentence contributes useful selection or invocation information; no filler or repetition is present.

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?

Given a one-parameter read-only tool with an output schema, the description covers purpose, when to use and avoid, sibling alternatives, data included, and accepted parameter formats. Nothing an agent needs to select or call the tool correctly 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 description coverage is 0% and the schema only defines `date` as an unconstrained string/null. The description fully compensates by documenting accepted formats ('YYYY-MM-DD', 'today', 'yesterday', or an offset like '-1') and the default ('Defaults to today'), which is essential for correct invocation.

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 immediately states the decision it supports ('Whether the user should train hard today or hold back') and then enumerates the exact Garmin metrics it returns. It explicitly distinguishes itself from siblings like get_plan, the activity tools, get_sleep_data, and get_daily_summary, so an agent can route correctly without opening 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 both the positive trigger ('For that question, and for checking today before prescribing a hard session') and explicit exclusions ('Not for reviewing a week, a run or how training is going: get_plan and the activity tools answer those'). It also states that get_sleep_data and get_daily_summary are unnecessary alongside it, which is precise alternative guidance.

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