repl_list

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 the tool lists sessions and their statuses, but does not disclose what 'statuses' means, whether it includes session IDs, or any side effects (e.g., whether it is read-only). This is a simple listing operation, but without annotations, the agent cannot infer safety or data details.

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 a single concise sentence that is front-loaded with the verb 'List' and the resource. There is no waste, and it is appropriately sized for a tool with no parameters and a straightforward purpose.

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 is simple (zero parameters, no output schema), and the description is brief. It does not describe the output format in detail, but without an output schema, some return value information would be beneficial. However, for a simple listing tool, this is minimally complete, lacking details on what constitutes a 'status' or if any login is required.

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?

The tool has zero parameters, so the description does not need to explain parameters. With no parameters, schema coverage is 100% by default, and the description adds the semantics of what is returned: 'sessions and their statuses,' which is useful. This is a baseline 4 for zero-parameter 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?

The description 'List active REPL sessions and their statuses' clearly states the action (list) and the resource (active REPL sessions), adding 'and their statuses' to specify the scope. It distinguishes itself from sibling tools like repl_spawn or repl_kill, which perform actions, and from repl_list alone, though it does not explicitly differentiate from a potential sibling that lists all 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 implies usage when you need to see active sessions, but it does not provide explicit when-to-use or when-not-to-use guidance. There are no alternatives mentioned, but given the sibling set, it is clear this is for listing, not managing sessions. It is minimally adequate but lacks explicit context.

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