get_coach_plan

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 real context beyond that: the data originates from the athlete's wearable (Garmin Coach) and functions as the source of truth for runs. It omits behavioral edge cases such as what happens when no plan exists or data is stale, but for a read-only getter this is adequate.

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?

A single, front-loaded sentence that leads with what the tool returns and follows with the enumerated payload. Dense but every clause carries information; the trailing ownership sentence is the only slightly indirect part.

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?

An output schema exists, so return-value explanation is not required, and the description correctly covers the data's origin. However, for a tool with an undocumented parameter and an open-world external data dependency, it should state the days_ahead window and the empty/no-plan case.

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?

There is one parameter, days_ahead (default 7), with 0% schema description coverage, and the description never mentions it. It refers to 'upcoming workouts' without tying that window to days_ahead, so an agent must guess at the parameter's semantics and defaults.

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?

Names a specific resource (Garmin Coach plan from the wearable) and enumerates its contents: phase, week number, event date, today's and upcoming workouts with HR/pace targets, and run consistency. An agent knows exactly what it gets. Sibling differentiation is only implicit via the note that 'the coach plan owns the runs; plan stations and classes around it' — no sibling tool is named.

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?

Usage is implied by the ownership statement ('plan stations and classes around it'), suggesting this is the anchor when planning other sessions. There is no explicit when-to-use/when-not, no mention of what to do if no coach plan is connected, and no routing to alternatives like get_training_summary or get_progress.

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