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

Annotations already declare readOnlyHint=true, destructiveHint=false and a closed-world scope, so the safety profile is covered. The description adds genuine value beyond them by disclosing the breadth of what is returned: the on/off state, message text, and any schedule or restriction, which tells the agent this is a richer read than a bare boolean.

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?

One front-loaded sentence with the verb leading, and the dash-delimited clauses enumerate the returned facets efficiently. Slightly dense phrasing, but every clause carries information.

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 with a full output schema and complete annotations, the description covers purpose and returned scope without redundant return-value detail. Nothing an agent needs to call it correctly is missing.

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?

There is a single parameter, mailbox, fully documented in the schema as a name or email address (100% coverage). The description adds nothing about the parameter itself, so the baseline of 3 applies - 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?

The description names a specific verb (read) and resource (the automatic vacation/out-of-office reply) and enumerates what is inspected: whether it fires, its text, and its schedule or restrictions. The read framing implicitly contrasts with settings_update_vacation, though no sibling is named outright.

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?

Use is implied - inspect a given mailbox's vacation responder - but there is no explicit when-to-use, when-not, or named alternative such as settings_send_as_find or settings_filters_list for other settings inquiries. The agent must infer that this is the read-only counterpart to settings_update_vacation.

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