cancel_timer

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It does not state whether cancellation is immediate, whether it is idempotent, what happens if the timer already fired or the ID is invalid, or what the response contains. For a state-mutating tool, this is a notable gap.

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?

A single short sentence with zero filler, and the action is front-loaded. It is efficient, though the brevity leans toward under-specification rather than disciplined conciseness.

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?

An output schema exists, so return values need not be described, but with no annotations and an undocumented required parameter, the definition should disclose mutation semantics and failure behavior. As written it leaves the agent without enough context for a destructive operation.

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 with 0% schema description coverage, so the description must compensate. It partially does by indicating the timer_id originates from list_timers, but adds no format or type detail beyond the schema's string type.

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 (cancel) and resource (timer), and implicitly separates itself from the read-oriented list_timers and the create/modify-oriented set_timer in the sibling set. It does not explicitly name an alternative to use instead, but the action is unambiguous.

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?

"from list_timers" implies the prerequisite that the timer_id must first be obtained via list_timers, which is useful implied guidance. However, there is no explicit statement of when to cancel versus modify a timer with set_timer, nor any error/exclusion conditions.

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