jules_cancel_session

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

With no annotations provided, the description carries full burden for behavioral disclosure. 'Cancels' implies a destructive mutation, but it doesn't specify whether this requires special permissions, if the action is reversible, what happens to associated resources, or what the response looks like. The description is minimal and lacks important operational context.

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, efficient sentence that gets straight to the point with zero wasted words. It's appropriately sized for a simple operation with one parameter and no complex behavioral nuances to explain.

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 destructive operation tool with no annotations and no output schema, the description is insufficient. It doesn't explain what 'cancels' means operationally, what happens after cancellation, error conditions, or return values. Given the complexity of session management and multiple sibling tools, more context is needed for effective tool selection.

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% with the single parameter 'sessionId' documented as 'Session ID'. The description doesn't add any additional semantic context about the parameter beyond what the schema provides, such as format examples or where to obtain session IDs. With complete schema coverage, 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 clearly states the action ('Cancels') and target resource ('an active Jules session'), making the purpose immediately understandable. It doesn't explicitly differentiate from sibling tools like 'jules_get_session' or 'list_sessions', but the verb 'Cancels' strongly implies a destructive operation versus read-only alternatives.

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 provides no guidance on when to use this tool versus alternatives like 'jules_get_session' for checking status or 'list_sessions' for discovery. It mentions 'active' session but doesn't clarify prerequisites, error conditions, or what happens to inactive sessions.

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