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

With no annotations, the description carries the full burden and does well: it discloses that agent_token is returned only once, that the token must be reused on subsequent calls, the NAME_IN_USE failure mode and its fix, and that an idle name retains the same agent_id. It omits token lifetime/expiry and whether the token is a secret to protect, which is why it is not a 5.

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?

Five short sentences with the action front-loaded and the token contract stated before the edge cases. The telegraphic style ('Returns agent_token once') is efficient, though the fragments read more like notes than prose.

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?

There is no output schema and no annotations, so the description must explain the return contract — which it does for agent_token and the error code. But for a 4-parameter tool with zero schema coverage it leaves two parameters and role semantics unexplained, so an agent cannot call it fully informed.

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?

Schema description coverage is 0% across 4 parameters, so the description must compensate and largely does not. It only touches 'name' (implicitly unique on a shared key) and 'role' via the optional 'role?' notation; session_id and client_hint are never mentioned anywhere and remain completely opaque.

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 states a concrete verb and resource — naming yourself on a shared key — and immediately shows the signature 'identify(name, role?)'. None of the sibling tools (board_act, consult, turn, cube_*) do identity registration, so the purpose is distinguishable. The phrasing 'on a shared key' is slightly metaphorical, which keeps it from a 5.

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?

It gives lifecycle guidance: 'Pass agent_token on every later call' establishes this as a prerequisite step, and 'NAME_IN_USE: take the suggested -2 name' prescribes recovery. However, it never explicitly says 'call this before any other tool' or when not to call it, and gives no guidance on choosing a name or role.

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