Advanced: seal a session

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

The annotations only indicate readOnlyHint=false, so the description carries the burden of behavioral disclosure. It states that sealing blocks further exec, which is a useful effect. However, it does not disclose whether the action is reversible, whether special permissions are required, or what happens to the session object. For an 'advanced/internal' tool, more transparency about side effects and irreversibility would be expected.

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?

The description is a single sentence with a bracketed tag, front-loading the action and its effect. There is no filler or redundancy; every word contributes to understanding the tool's purpose and usage. The structure is efficient and easy to parse.

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?

Given the tool has one required parameter, no output schema, and minimal annotations, the description needs to cover parameter semantics, return behavior, and any caveats. It explains the action and usage preference but omits what session_id means, what the tool returns (if anything), and clarifies the meaning of 'raw session.' For an advanced tool, this is a significant gap that could lead to misuse.

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?

The input schema provides zero description for session_id (coverage 0%), and the description does not mention the parameter at all. It gives no indication of what session_id refers to, how to obtain it, or its format. The description focuses entirely on the action, leaving the sole parameter completely ambiguous and forcing the agent to guess from the parameter name alone.

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 clearly states the action ('Seal a raw session') and its immediate effect ('Further exec is rejected'). This is a specific verb+resource combination that distinguishes it from sibling tools like runtime_session_open, runtime_session_exec, and runtime_session_receipt, all of which have different purposes.

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 provides explicit guidance: 'Prefer leaving sessions to expire unless the user asked to close.' This tells the agent when to use the tool (only when explicitly requested) and implies the default alternative (letting sessions expire naturally). While it doesn't name specific sibling tools, the condition is clear and actionable.

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