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

With no annotations provided, the description takes on the full disclosure burden. It clearly states the 25-per-owner quota, that the UUID is a one-hour discovery capability and not a telemetry credential, and that the checks 'only display allowlisted system facts and install nothing.' It doesn't mention reversibility or permissions, but it is far more transparent than typical for this tool type.

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 three sentences, front-loaded with the core action and scoping limits. The sentence about passos.posix/passos.powershell is cryptic and references a parameter that does not exist in the schema, which costs a point; otherwise every sentence earns its place.

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 and no annotations, the description covers purpose, owner quota, UUID semantics, and non-invasive behavior. It doesn't describe a return value or the idempotency behavior that the schema already covers, but an agent has enough to decide whether and how to call 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?

Schema description coverage is 100%, so the baseline is 3. The description adds useful meaning to request_id ('one-hour discovery capability; not a telemetry credential') and to the overall registration limit, but it doesn't elaborate on nome or grupo. The 'passos.posix or passos.powershell' reference points to a target terminal concept absent from the schema, which slightly muddies parameter understanding.

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 'Register a device UUID before discovery and collector selection,' which names a specific verb, resource, and workflow stage. It further differentiates itself from siblings like create_guest by stating 'maximum 25 per owner, creating a guest if needed,' making the tool's scope distinct.

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 provides temporal context ('before discovery and collector selection') and a terminal hint ('Choose passos.posix or passos.powershell'), but it never explicitly names an alternative tool or says when not to use this one. The phrase 'creating a guest if needed' implies overlap with create_guest without giving a selection rule.

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