cancel_execution

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

Annotations already declare destructiveHint=false, idempotentHint=false, and openWorldHint=true, but the description adds genuinely useful behavior: cancellation does not roll back completed stages, and a confirmation message is returned. These effects go beyond the annotation set and materially affect how an agent uses the tool. It stops short of covering permissions or what happens to queued stages.

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, front-loaded with the core action, then the use case, then the critical caveat and return value. No sentence is wasted, and the important non-rollback limitation is stated plainly.

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 two-parameter mutation tool with no output schema, the description supplies the return value and the key side-effect caveat, and annotations cover the safety profile. Slightly incomplete in that it says nothing about the non-idempotent behavior the annotations flag or what happens to not-yet-started stages.

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 100%, so both parameters (execution_id, reason) are already fully documented in the schema. The description's 'by its ID, optionally providing a reason' merely restates that, adding no format or syntax detail. Baseline 3 applies.

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 (running pipeline execution) with the scoping constraint 'by its ID'. It is clearly distinct from read siblings like get_execution/list_executions, but it never explicitly distinguishes itself from pause_execution, the closest sibling, leaving the agent to infer the difference.

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?

Gives concrete when-to-use guidance: 'Use this to stop a deployment in progress — for example, when a bad build was triggered.' That is clear context, but there is no when-not guidance or reference to alternatives such as pause_execution or restart_stage.

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