garmin_status

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds useful behavioral context beyond that: it exposes session/logout timing, sync staleness, and the last error, which tells the agent this is the diagnostic entry point. It does not describe output shape, but that is largely captured by the enumerated fields.

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 sentences, front-loaded with what the tool reports, followed by the routing advice. Every clause carries information and nothing is repeated from the annotations or schema.

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 no output schema, the description must convey what comes back, and it does so by listing the four reported facts. For a zero-arg read-only diagnostic, this is close to complete; only pagination/format details are absent, and those are irrelevant here.

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 tool takes zero parameters, so there is nothing for the description to disambiguate; baseline 4 applies. No parameter text is needed or missing.

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 diagnostic operation ('login and connection check') and enumerates exactly what it reports: who is logged in, login lifetime, last watch sync, and last error. This is clearly distinguishable from the data-retrieval siblings like garmin_activities or garmin_devices.

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 concrete trigger conditions: 'Call this first when another Garmin call fails, or to see how current the data is.' That is explicit when-to-use guidance. It stops short of a 5 because it does not name a specific sibling as an alternative or state when not to bother calling it.

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