set_vacation

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

With no annotations, the description carries the behavioral burden and does meaningful work: it discloses the non-obvious rate-limiting/suppression behavior ('Fires at most once per sender within a rolling window (standard RFC 5230 semantics)') and the enabling precondition. It could also mention overwrite semantics or auth requirements, but the disclosed behaviors are 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?

Two sentences, no fluff: the first names the core operation, the second adds the essential constraint and behavioral nuance. Every clause earns its place and the most important information is front-loaded.

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 tool with no annotations and no output schema, the description covers the main action and a critical behavioral limit, but it leaves gaps: subject is not explained, return/error behavior is absent, and the relationship to get_vacation is not explicitly addressed. Given the modest parameter count, the missing subject semantics keep it from being fully complete.

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 about 60% and the schema already documents domain and message. The description reinforces that message is required when enabling, which adds slight value for the enabled-message interplay, but it does nothing for the subject or enabled parameters and does not clarify behavior beyond the schema.

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?

States a specific verb and resource: 'Enable/disable and configure a mailbox's vacation auto-reply.' The action is unambiguous and pairs naturally with the sibling get_vacation for reading the current state, so an agent can distinguish it without opening the schema.

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 clear context for when to set or modify vacation auto-reply, and includes a key condition ('A message is required when enabling'). However, it never explicitly contrasts this with get_vacation or says when not to use it; differentiation is implied rather than stated.

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