List REPL sessions

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

No annotations are provided, so the description carries the full burden. It states that all sessions are listed and that pid, workspace, and liveness are included, which implies a read-only, comprehensive operation. It does not explicitly state side effects or output format, but for a simple list operation the behavioral surface is well covered.

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?

A single, tightly worded sentence that front-loads the action and resource, then specifies the returned fields. No filler or redundant information.

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 zero-parameter list tool, the description adequately covers purpose and output fields. It does not specify response formatting or error behavior, but with no output schema and such a simple operation, the missing details are minor.

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?

There are zero parameters, so the baseline is 4. The description adds useful context about the fields returned, even though it does not explain any parameters (there are none to explain).

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 uses a specific verb ('List') and identifies the resource ('REPL sessions') while naming the returned fields (pid, workspace, liveness). This clearly distinguishes it from siblings like create_session and remove_session by operation, and from history/exec by resource.

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?

Usage context is implied: use this when you need to enumerate all REPL sessions. However, there is no explicit mention of when not to use it or how it compares to alternative tools like history or exec, so the guidance is only implicit.

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