end_session

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

Description lists specific side effects (stops billing, safety_restore, closes apps) beyond annotations, which already include destructiveHint and openWorldHint. Also notes that further calls on session_id will fail.

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?

Three sentences cover purpose, side effects, and usage guidelines with no fluff. Front-loaded key action.

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 destructive tool with one parameter and no output schema, the description is complete: it covers what it does, side effects, when to use, and consequences of 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?

Only one parameter with full schema coverage and description. The tool description does not add additional semantic meaning beyond what the schema provides, but no extra info is needed.

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?

Description clearly states 'End an active session' with specific verb and resource. It distinguishes from sibling tools like start_session by being the explicit counterpart.

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?

Explicitly states when to call ('when finished or abandoning') and warns not to call twice. Provides clear usage context without needing alternatives.

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