pi_end_session

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

With only readOnlyHint=false and destructiveHint=false, the annotations provide no meaningful behavioral detail. The description states the action but does not disclose whether ending a session is reversible, whether unsaved work or open windows are affected when close_windows is not true, or what side effects occur beyond ending the session.

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 focused sentence that front-loads the primary action and then mentions the optional parameter. There is no wasted wording.

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 simple one-parameter, no-output-schema tool, the description covers the essential action and optional behavior. It is not fully complete because it omits return-value expectations, prerequisites, and what happens when there is no active session, but these gaps are minor given the tool's simplicity.

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 schema only defines close_windows as a boolean with no description; the tool description partially compensates by indicating that closing image windows is optional. However, it does not explicitly state the meaning of true versus false or the default behavior when the parameter is omitted.

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 verb ('End') and the resource ('the current session') and adds the optional window-closing behavior. However, it does not explicitly differentiate itself from sibling tools like pi_stop or pi_restart, so it is clear but not fully distinguished.

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?

No guidance is given about when to use pi_end_session instead of related tools such as pi_start_session, pi_use_session, pi_stop, or pi_restart. The description does not mention whether an active session is required or what happens if one is not active.

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