Finish signing in to Garmin

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

Annotations only indicate readOnlyHint=false and destructiveHint=false. The description adds meaningful behavioral context: the code is emailed, valid for 30 minutes, and successful submission leads to saved tokens lasting about a year. It doesn't detail what happens on an invalid code, but the provided auth lifecycle context is valuable.

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 compact and front-loaded: the first sentence states the core purpose, and the second supplies the trigger condition and validity details. No filler or redundant restatement of the tool name 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?

For a one-parameter auth-completion tool, the description covers the essential context: when to call, what the code is, how long it is valid, and what to expect logistically. The presence of an output schema means the description doesn't need to explain return values.

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 coverage is 0%, so the description must clarify the code parameter. It does so by identifying the code as the one-time emailed code and adding the 30-minute validity constraint, which goes beyond the schema's bare 'Code' label. This is adequate for a single, simple parameter.

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 states a specific action ('Finish signing in to Garmin') with a specific method ('the one-time code it emailed'), making the tool's purpose immediately clear. The trigger condition ('Only needed when a Garmin tool has just reported that a code was sent') distinguishes it from the many data-retrieval sibling tools.

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 description gives an explicit when-to-use condition: only after a Garmin tool reports that a code was sent. It also provides the code's 30-minute validity window and notes that this step won't be needed again for about a year, which helps the agent decide whether to call this tool now or avoid it.

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