peers

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

With no annotations, the description carries the full burden and does so well: it discloses that `status_unreadable` peers are reported busy as a safe default and must not be reported as observed fact, that this session is never in the list, and that `self` is the address that reaches it. These are non-obvious behaviors an agent would otherwise get wrong.

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?

Front-loaded with the purpose sentence, and nearly every following sentence carries a distinct directive. It is on the dense side, packing display-label guidance, identity guidance, and version guidance into an unbroken block, but little of it is waste.

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?

No output schema exists, and the description adequately covers the return shape (name, state enum, working directory, durable id, tincan_version and per-peer versions) plus the identity edge case of `self`. Nothing critical for correct invocation is missing.

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?

Zero parameters, so the baseline is 4. The description instead adds semantics for related identifiers (name vs display_label vs durable ID, and the self address send_peer accepts), which is useful but pertains to a sibling tool's inputs rather than this call's schema.

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 the live Codex, Claude Code, and opencode sessions on this machine') and immediately narrows scope to sessions 'you can message'. It also implicitly distinguishes itself from siblings by positioning the call as a prerequisite to send_peer.

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?

Gives explicit when-to-use guidance ('Call this before send_peer: names change and sessions come and go') and an explicit when-not-to-do-something-else ('report those rather than shelling out to `tincan --version`'). The agent knows both the trigger and the better alternative.

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