Jules MCP Server

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 describes the creation action and mentions that Jules will wait for plan approval if required, which adds useful context. However, it does not cover other behavioral aspects such as authentication needs, rate limits, error conditions, or what happens if the session creation fails, leaving gaps in transparency.

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 well-structured and front-loaded with the core purpose, followed by clear sections for 'Args' and 'Returns'. Every sentence earns its place by providing essential information without redundancy, making it efficient and easy to parse for an AI agent.

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?

Given the complexity of a session creation tool with 5 parameters and no annotations, the description does a good job covering purpose, parameters, and return values. Since an output schema exists, the description need not detail return values extensively. However, it could improve by addressing potential errors or prerequisites, making it slightly incomplete for full contextual understanding.

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 0%, so the description must compensate. It provides meaningful semantics for all parameters: 'prompt' as the coding task description, 'source' as the resource name, 'branch' as optional with default behavior, 'title' as optional with auto-generation, and 'require_plan_approval' explaining its effect. This adds significant value beyond the bare schema, though it could include more details like format examples for 'source'.

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 specific action ('Create a new Jules session') and the resource ('to work on a coding task'), distinguishing it from siblings like 'get_session' or 'list_sessions' which retrieve existing sessions rather than creating new ones. The verb+resource combination is precise and unambiguous.

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 implies usage context by specifying 'to work on a coding task' and mentions the 'require_plan_approval' parameter behavior, but it does not explicitly state when to use this tool versus alternatives like 'send_message' or 'create_pull_request'. It provides clear context for initiating a session but lacks explicit exclusions or comparisons to sibling tools.

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