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

With no annotations, the description carries the full burden. It does disclose a genuinely useful trait: cancellation is a request that is applied between steps, so it is asynchronous and best-effort. It omits permissions required, idempotency, whether cancellation can be undone, and what happens if the run completes first.

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 front-loaded sentence that names the action, the target, and the timing caveat, with zero 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 simple two-parameter mutation with no annotations and no output schema, the description covers the core action and its latency semantics. Missing are the success response behavior (immediate acknowledgement vs. confirmation of stop) and the handling of already-terminated runs.

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 0%, both parameters are required strings, and the description never mentions pipeline_id or run_id. The names are suggestive, but an agent gets no confirmation of whether pipeline_id is needed for scoping/auth or how the pair must relate.

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: cancelling an active pipeline run, which is distinct from pipeline_run, pipeline_run_wait, and pipeline_run_get in the sibling list. It never explicitly contrasts with those siblings, though, so it stops short of a 5.

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 phrase 'of an active run' implies the precondition that only in-flight runs qualify, and the name signals the context. There is no explicit when-not guidance (e.g. what to do for a queued or already-finished run) and no named alternative.

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