iam_timer_cancel

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

No annotations are provided, so the description carries the full burden. It identifies the action as cancelling a timer and scopes it to a mailbox, but it does not disclose error behavior, irreversibility, idempotency, or what happens if the timer_id is invalid or missing. This is thin for a destructive-looking operation.

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 a single sentence with no wasted words, and it starts with the primary verb 'Cancel', giving immediate focus. It is appropriately sized for a one-parameter tool.

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 cancel operation with an output schema present, the description captures the essential action and scope in a compact form. It omits edge-case details like error handling, but given the tool's simplicity and the presence of an output schema, this is mostly sufficient.

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 description coverage is 0%, so the description should compensate for the lone parameter, timer_id. The description only indirectly refers to a timer and never explains what timer_id is, where to obtain it, or what constraints apply. The field name is self-explanatory, but the description provides almost no additional parameter semantics.

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 uses a clear verb ('cancel') and a specific resource ('timer'), and adds a meaningful scope qualifier ('created by or targeted to this mailbox'). It distinguishes from set/list tools, but it does not explicitly differentiate from the similarly named sibling 'iam_timer_clear', so there is slight ambiguity.

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 no direct guidance about when to use this tool versus siblings like iam_timer_clear, iam_timer_snooze, or iam_timer_set. The only contextual hint is the word 'outstanding', which implies a pending timer, but that is simply inferred from the purpose. No alternative routing or exclusion is offered.

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