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

With no annotations provided, the description fully carries the behavioral disclosure burden. It explains semantic nuances beyond a simple list: `address` can change due to renames, `agentId` is stable, and `send_message` can strand messages because it doesn't wake the recipient. It also discloses what the tool returns (status fields, brandKey, ownerAddress) and explicitly states it takes no arguments. This is rich, honest behavioral context.

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 long but every sentence serves a purpose — no filler. It is front-loaded with the core function, uses bullet points for the three identity fields, and ends with a clear rule of thumb. The length is justified by the need to explain subtle identity semantics and cross-tool warnings.

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?

Given no output schema, the description compensates by detailing the returned fields: identity fields (`name`, `address`, `agentId`), status indicators (`online`/`alive`/`listening`), `brandKey`, and `ownerAddress`. It also covers usage context, cross-tool interactions, and storage best practices. The tool is simple (no args) and the description fully equips an agent to use it correctly.

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 and the schema is an empty object. The description explicitly states 'Takes no arguments,' which is the only relevant semantic. Per the rubric, 0 params gets a baseline of 4, and this description adds an explicit confirmation, so a 5 is appropriate.

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 opens with a specific verb and resource: 'Lists the agents you can reach — your own agents AND agents shared to you from other owners.' It clearly distinguishes itself from messaging tools by directing users to `message_teammate` for messaging, and it explicitly contrasts with `send_message`. The scope is unambiguous, covering both own and shared agents.

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?

Provides explicit when-to-use guidance: to see reachable agents. It also gives concrete alternatives and exclusions: 'To MESSAGE any of them, use the `message_teammate` tool' and 'Do NOT use send_message for an agent — that path does not wake them.' Additionally, it prescribes which identity field to use for different purposes ('read the name, use the `agentId` to message and to store'), which is actionable usage direction.

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