List Sessions

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint=false, so the safety profile is fully covered. The description adds the recovery use case but its field enumeration largely duplicates the existing output schema, and it says nothing about session lifetime, ordering, or limits.

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?

Three terse clauses, front-loaded with the verb and resource, with no wasted prose. The only minor redundancy is re-listing fields that the output schema already defines.

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?

With an output schema present the return values need not be explained, annotations carry the safety profile, and there are no parameters, so the description is nearly complete. The remaining gap is minimal: no mention of empty-result or error behavior for a session list.

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 takes no parameters and schema coverage is 100%, so the required baseline is 4. 'No arguments' correctly confirms the empty-input contract and there is nothing further for the description to disambiguate.

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?

States a specific verb and resource ('List live sessions') and enumerates the returned fields (session_id, pid, argv, done, exit_code, timestamps), which clearly separates it from the action-oriented siblings like exec_poll, exec_wait, and exec_kill. It stops short of naming an alternative sibling, so it is clear but not explicitly differentiated.

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?

'Recovers ids after a lost reply' gives a concrete when-to-use scenario, which is the key selection cue for a listing tool. It does not state exclusions or name named alternatives, so it is clear context rather than full when/when-not guidance.

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