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

With no annotations, the description carries the full burden and does disclose the critical behavioral trait: 'session' (the default) destroys the sandbox entirely while 'task' is non-destructive and leaves the session idle. It omits other traits such as whether stopping an already-idle session errors, idempotency, or auth requirements.

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?

Two sentences, front-loaded with the action and then the strategy semantics; no filler and no redundancy. Every clause earns its place by resolving the task-vs-session ambiguity.

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 2-parameter tool with no output schema and no annotations, the description covers the destructive default and the two modes adequately. Return/response behavior and failure modes are absent, but an agent has enough to call it correctly and safely.

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, but the description adds meaning beyond the schema text by spelling out the practical consequence of each enum value ('session stays idle for follow-ups') and restating that 'session' is the default. That consequence framing is genuinely useful rather than pure repetition.

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 ('Stop a running session') that an agent can immediately distinguish from run_session, send_task, and the get_/list_ readers. It stops short of naming a sibling or scoping the tool explicitly, so it is clear but not fully differentiated.

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 description explicitly routes between the two strategies: 'task' to stop only the current task and keep the session idle for follow-ups, 'session' (default) to destroy the sandbox. That is concrete when-to-use guidance for the main decision an agent faces, though it does not discuss prerequisites or error conditions.

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