create_session

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It explains the core behavior (creating sessions for code tasks) and the repoless session option, but doesn't disclose important behavioral traits like authentication requirements, rate limits, whether sessions are persistent, what happens on failure, or expected response format. The description adds basic context but leaves significant gaps.

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 perfectly concise with just two sentences that each earn their place. The first sentence states the core purpose, and the second explains the important 'repoless session' nuance. No wasted words, and the most critical information is front-loaded.

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 5-parameter creation tool with no annotations and no output schema, the description provides adequate but incomplete context. It explains the tool's purpose and the repoless session concept well, but doesn't address what the tool returns, error conditions, or important behavioral constraints. Given the complexity of session creation and the lack of structured metadata, more completeness would be beneficial.

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?

With 100% schema description coverage, the input schema already documents all 5 parameters thoroughly. The description adds some semantic context by explaining the relationship between repo/branch parameters and the 'repoless session' concept, but doesn't provide additional meaning beyond what's already in the schema descriptions. This meets the baseline for high schema coverage.

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 tool's purpose with a specific verb ('creates') and resource ('new Jules session or automated run'), and distinguishes it from siblings by explaining the unique 'repoless session' capability. It explicitly differentiates this creation tool from session query/management tools like 'get_session_state' or 'list_sessions'.

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 clear context about when to use this tool (to create sessions for code tasks) and explains the alternative 'repoless session' approach when repo/branch are omitted. However, it doesn't explicitly state when NOT to use this tool versus alternatives like 'jules_quick_task' or 'jules_create_and_wait' among the siblings.

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