session_end

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

No annotations are provided, so the description carries the burden of explaining behavior. It discloses that the session is closed and that a summary can be captured as a memory, which covers the main side effects. However, it does not clarify whether closing is irreversible, what happens to the session record, or how the summary memory is stored or retrieved.

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-load the primary purpose and usage timing. Every word earns its place; no redundancy or filler exists.

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 tool with zero required parameters, no output schema, and 100% schema parameter coverage, the description adequately explains the core behavior and invocation time. It could mention that the session should not be used afterward, but this is not a significant gap given the sibling context and tool 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?

Schema description coverage is 100%, so the schema already documents 'tags' and 'summary' with meaningful descriptions. The tool description does not add further parameter-level detail, such as expected tag formats or relationships between the two parameters, so the baseline score of 3 is appropriate.

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 uses a specific verb ('Close a session') and identifies the resource and optional action ('capture a summary'). This clearly distinguishes it from siblings like session_start and session_checkpoint.

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 states when to call it: 'at the end of a conversation to record what was accomplished.' It does not explicitly discuss alternatives or when not to use it, but the timing guidance is clear and sufficient for a simple closure tool.

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