garmin_submit_mfa_code

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

Annotations already show this is not read-only and not destructive. The description adds useful behavioral context beyond those hints: the code expires in 30 minutes, successful submission establishes tokens lasting about a year, and the prompt should not recur. It does not cover invalid-code handling, but the annotations lower the burden.

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 three tight sentences with no filler. The main purpose is front-loaded, followed by a concrete usage trigger and useful lifecycle details.

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 authentication helper with an output schema present, this is complete: it states what the tool does, when it is needed, where the code comes from, how long it remains valid, and how often the user will see this step.

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 compensate. It does by explaining that the 'code' parameter is the one-time code sent by email. This adds real meaning beyond the schema's bare string type, even though it does not specify length or format.

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 verb and resource: 'Finish signing in to Garmin with the one-time code it emailed.' This clearly identifies an MFA completion action and distinguishes it from the data-retrieval and workout-management 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?

It explicitly says when to use the tool: 'Only needed when a Garmin tool has just reported that a code was sent.' This is an unambiguous trigger condition and also implies that it should not be used otherwise.

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