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

Annotations already signal destructiveness, and the description adds a meaningful behavioral trait: idempotency on terminal states. This tells the agent that cancelling an already-terminal ticket is safe/no-op, which is valuable context beyond the structured fields.

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?

Three short sentences, each earning its place: the core action and scope, the idempotency caveat, and the sibling-tool alternative. The most important information is front-loaded and there is no filler.

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 cancellation tool with an output schema and destructive annotations, the description covers the scope, edge-case behavior, and correct sibling routing. Nothing essential is missing for an agent to select and invoke the tool correctly.

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?

With 0% schema description coverage, the description carries the burden of explaining `ticket_id`. It implicitly defines the parameter as a single-action ticket identifier (`tkt_*`) and indicates that terminal tickets should not be cancelled, adding real semantic meaning beyond the bare 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?

The description uses a specific verb ('Cancel') and resource ('non-terminal ticket') and distinguishes this tool from the sibling for multi-step jobs. It also clarifies the ticket naming convention (`tkt_*`), making the tool's scope immediately identifiable.

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?

It explicitly states when to use this tool (non-terminal single-action tickets) and when not to, routing `job_*` multi-step plans to actionlayer_cancel_job instead. This direct alternative guidance leaves no ambiguity for the agent.

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