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 the backing service path (`/trainingplan-service/trainingplan/fbt-adaptive/...`), which is useful provenance but says nothing about auth requirements, error behavior when the id is invalid, or what the returned plan contains.

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?

Two tight, front-loaded sentences with no filler; the resource and scope come first and the disambiguation follows. The raw REST path is arguably implementation detail an agent caller never uses, which slightly dilutes an otherwise efficient definition.

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 single-parameter read-only lookup with no output schema, the definition covers identity and the sibling boundary adequately. It leaves implicit what shape the returned plan takes (workouts, phases, status), a minor gap given no output schema exists to carry that.

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 100% (the single `planId` param is documented as a numeric id), so the schema carries the parameter semantics. The description's 'by id' restates rather than extends that, which is the expected baseline when the schema does the work.

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 specific resource (one adaptive/Garmin Coach training plan), the lookup key (by id), and explicitly separates itself from the sibling `get_training_plan_by_id` by naming its distinct API sub-path. An agent can distinguish the two tools without opening either 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?

The comparison to `getTrainingPlanById`'s `phased` path tells the agent this is the correct tool for adaptive plans specifically, which is genuine alternative-aware guidance. However, it stops short of an explicit when-to-use/when-not statement (e.g. 'use this when the plan is a Garmin Coach adaptive plan').

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