Continue a session

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

Annotations already indicate readOnlyHint=false and idempotentHint=false, so the description doesn't need to repeat that. It adds useful context: the session id stays server-side (so the agent only needs jobId) and that the job must be finished. It also clarifies the return value (new jobId). No contradiction with annotations.

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 two sentences, front-loaded with the core purpose. It includes the key input (jobId) and output (new jobId) without unnecessary verbosity. Every word adds value, and it is well-structured for quick scanning.

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?

The tool has 5 parameters and no output schema, yet the description explains only the core flow. It omits guidance on optional parameters (model, effort, waitSeconds) and does not describe how to use the returned jobId (e.g., poll status). An agent would need to infer or look elsewhere for critical details, making it incomplete for reliable invocation.

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 only 20% (only jobId has a description). The tool description only mentions jobId and the return value, but does not explain prompt, model, effort, or waitSeconds. With such low schema coverage, the description must compensate, but it fails to clarify the purpose or constraints of the other parameters.

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: 'Start a follow-up turn in an existing session.' It specifies the resource (existing session via a finished job's jobId) and the outcome (returns a new jobId). It distinguishes itself from likely siblings like claude_run (which would start a new session) by emphasizing 'follow-up turn' and 'existing session.'

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 gives a clear context: it takes the jobId of a finished job, implying it is for continuing completed work. However, it does not explicitly mention alternative tools or conditions for when not to use it. The guidance is sufficient for an agent to infer the appropriate scenario, but lacks explicit exclusions.

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