Create a new Jules session

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

Annotations already convey mutation with readOnlyHint=false and idempotentHint=false. The description adds no behavioral context beyond 'create', such as whether creation is asynchronous, whether it returns a session ID, whether it starts background work, or what side effects occur. With no output schema, this is a meaningful gap.

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?

Single concise sentence with no wasted words; it front-loads the core action and resource. The only weakness is that it adds little beyond the title, but that does not detract from its tightness.

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?

Despite 9 parameters and no output schema, the description does not explain the return value, the session lifecycle, or what happens after creation. Given sibling tools like jules_monitor_session and jules_send_message, missing workflow context makes this definition incomplete for reliable 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 coverage is 100%, and the schema includes detailed descriptions for all 9 parameters, including automationMode's enum semantics and notes about PR creation. The tool description itself adds no parameter-level meaning, so it meets the baseline for schema-heavy tools.

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: create a new Jules coding session for a GitHub repository. It is clearly a create/start operation and is distinguishable from sibling get/list/delete tools, though it could be strengthened by explicitly mentioning the first step in a session workflow.

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?

No guidance on when to use this tool versus alternatives, such as when to choose jules_send_message or jules_get_session. The description implies creation is for starting work, but provides no exclusions or workflow context.

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