gmail_set_vacation

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

With no annotations at all, the description carries the full burden and largely meets it: it discloses that enabling causes Gmail to auto-answer incoming mail (a real outward-facing side effect), requires confirm=true, and that the return value is the state read back from the screen. It stops short of saying how soon the responder takes effect or whether existing pending mail is answered.

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?

Front-loaded with what the tool does, then side effects, then the confirm precondition — good ordering. The only waste is the duplicated confirm message ('outward-facing: needs confirm' followed by 'Requires confirm=true (outward-facing or destructive)'), which repeats the same fact twice.

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 an 8-param, no-annotation, no-output-schema mutation tool, the description covers the gaps that matter: the real-world side effect, the safety precondition, partial-update behavior, and what the call returns. An agent can invoke this correctly without further inference.

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 100%, so the baseline would be 3, but the description adds genuinely additive semantics: fields left out keep their current value, which defines partial-update behavior for the seven optional params that the schema does not state. This is exactly the kind of cross-parameter rule the schema cannot express.

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 verb+resource pair ('Turn the vacation responder ... on or off and set its dates and text') and parenthetically defines the concept as an out-of-office auto-reply. It does not explicitly point at the read-only sibling gmail_vacation, but the 'set' framing makes the divide clear enough.

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?

Explains the activation semantics ('enabled' on/off) and the key operating rule that omitted fields keep their current value, which tells an agent it can do partial updates safely. It states the confirm=true precondition but gives no explicit exclusions or named alternative (e.g. use gmail_vacation to inspect current settings).

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