Cancel session

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

Adds substantial context beyond the annotations: it discloses the exact state transition, that a running stream is aborted, that the returned session envelope only populates id/agent_id/state, and that explicit confirmation is required. It also warns that runs can spend credits or trigger downstream actions, which annotations alone (destructiveHint, openWorldHint) do not convey.

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?

Front-loads the core action and state behavior, then adds response shape and confirmation guidance. Each sentence carries information, though the closing caution about resubmitting unknown outcomes is slightly advisory in tone rather than strictly definitional.

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?

No output schema exists, and the description compensates by explaining what the returned session envelope contains. Combined with the state-transition and confirmation details, an agent has everything needed to invoke this mutation 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?

Schema coverage is 100%, so the baseline is 3. The description adds meaning by framing `confirm` as an explicit-confirmation requirement and calling this an 'exact account operation', reinforcing the account/confirm semantics beyond the schema text.

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 (session) with the exact state machine it operates on: 'processing'/'queued' -> 'failed', with completed/failed sessions returned unchanged. This distinguishes it clearly from siblings like kill_flow, rename_session, and delete_skill.

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 when the tool has effect (in-progress sessions) versus when it is a no-op (already completed/failed), plus a strong usage constraint: never resubmit unknown outcomes automatically. It does not explicitly name alternative siblings or when to prefer them, so it falls short of a 5.

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