kin_session_end

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

Annotations already declare it is mutating (readOnlyHint false), idempotent, non-destructive, and not open-world. The description adds only that it is 'session plumbing for writes,' which contextualizes but does not disclose edge cases like behavior on a non-existent session or interaction with pending transactions. With annotations carrying the safety profile, a 3 is appropriate.

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?

Very short and efficient, with no wasted words. However, the actual action is in the second sentence while the vague 'Session plumbing for writes' is front-loaded, which slightly diminishes front-loading of the key instruction.

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 tool with no output schema and annotations covering safety, the description is minimally adequate. It does not clarify what happens to uncommitted transactions or staged data when the session closes, which is a notable gap given the sibling transaction tools.

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 single session_id parameter is already fully documented. The description adds no additional meaning about the UUID format, where to obtain it, or its role. Baseline 3 when schema does the heavy lifting.

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?

States a specific verb and resource: 'Close an open session.' This clearly distinguishes it from the sibling kin_session_start, and the name reinforces the action. The leading phrase 'Session plumbing for writes' is slightly opaque but does not obscure the core purpose.

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 phrase 'Close an open session' implies the condition that a session must already be open, but there is no explicit guidance on when to use this versus transaction commit/abort siblings, or what prerequisites exist. Usage is inferable but not spelled out.

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