session_end

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

With no annotations, the description carries the behavioral burden. It discloses the key side effect: ending the session automatically generates a 'compressed summary of all observations' and persists knowledge. However, it does not state whether the session becomes permanently inaccessible, whether the summary is returned, or any other consequential behavior beyond 'end' and 'summarize'.

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 well-structured with 'AUTOMATIC TRIGGERS' and 'WORKFLOW POSITION' sections, making the key guidance easy to scan. There is mild redundancy between 'ALWAYS CALL THIS when ending work' and 'Last tool to call when finishing work', but nothing is wasted.

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 terminal action with no output schema, the description covers the purpose, the parameter source, the timing, and the automatic summarization behavior. The only real gap is not describing what happens after the tool returns, but the low complexity and clear workflow position keep this from being a significant omission.

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%, so the description must compensate for the sole parameter. It does: 'session_id: The session to end (track this from session_start)' adds provenance and clarifies the value needed. It stops short of format or validation details, but for a single required string parameter this is adequate.

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 and resource: 'End the current session' and trigger automatic summarization, which goes beyond the tool name. It does not explicitly differentiate from the similarly named sibling 'end_session', but the automatic-summarization behavior provides some distinction.

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 gives explicit trigger conditions ('User indicates they're done', 'Session goal has been achieved', 'About to start unrelated work') and workflow positioning ('Last tool to call when finishing work'). It lacks explicit when-not-to-use or alternative-tool guidance, but the usage context is concrete and actionable.

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