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

Goes well beyond the destructive/idempotent annotations by disclosing billing semantics (finished rows stay and are charged, unused hold returned), the async status path cancelling→cancelled, and that the call itself is free. The polling instruction is exactly the operational context an agent needs to avoid prematurely concluding the run is stopped.

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 carrying distinct payload: action and scope first, billing consequences second, state transition and verification last. No restatement of the title and 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 single-parameter mutation with no output schema, the description supplies everything an agent needs: what gets cancelled, what it costs, what state to expect, and how to confirm completion. The absence of an output schema is compensated by the explicit status-transition and polling guidance.

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?

Only one parameter and schema coverage is 100%, with the schema itself noting the run_id comes from a run tool. The description adds no further meaning about the identifier, which is the correct baseline when the schema already fully documents the input.

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 (Stop) and resource (a run) with scope qualifier 'queued or running', so the agent knows exactly what it affects. It does not, however, differentiate itself from the sibling cancel_flow_run, leaving the agent to infer which cancel applies to which object type.

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 clear conditions for use (run is queued or running) and prescribes the follow-up loop via get_run with wait_seconds until status is cancelled. No explicit when-not-to-use or comparison against cancel_flow_run or retry_failed, so it stops short of full routing guidance.

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