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

Annotations already declare destructiveHint=true, so the mutating nature is known. The description adds useful consequence context ('Frees the slot for the user's IP'), but says nothing about irreversibility, what happens to in-flight orders/messages in that session, or the error case for an unknown/expired sessionId.

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 short sentences, front-loaded with the action and followed by the effect. Every clause earns its place with 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 one-parameter, no-output-schema tool with a destructiveHint annotation, the description covers the core action and side effect adequately. It is slightly thin on failure behavior and post-termination state, but nothing essential for correct invocation is missing.

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 0% and the single required parameter sessionId is never mentioned in the description. The parameter is arguably self-evident from the tool name, but the description does nothing to compensate for the documentation gap.

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?

The description states a specific verb+resource ('End a sandbox session') and adds the intent qualifier 'now instead of waiting for it to expire'. It distinguishes the tool from sandbox_create_session/sandbox_get_session by implication, though it never names a sibling outright.

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?

Usage is implied through the contrast 'instead of waiting for it to expire', which tells the agent this is the proactive-termination path. There is no explicit when-not guidance, no named alternative sibling, and no prerequisite (e.g. session ownership) stated.

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