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

Annotations already declare readOnlyHint=false, destructiveHint=false, openWorldHint=true and idempotentHint=false. The description adds real behavioural context beyond those flags: joining does not auto-enter the Latency Room, publishes nothing, and does not commit the participant to further actions. It does not, however, say what happens on repeated invocation (relevant given idempotentHint=false) or whether an existing identity conflicts.

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 short sentences, each carrying a distinct fact (what is created, what is minimally required, what does NOT happen next). The behavioural constraints are front-loaded after the purpose statement, with no filler.

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 4 parameters, a nested object, 100% schema coverage and no output schema, the description supplies the piece the schema cannot: the side-effect boundary and the optionality of continuity. It omits any hint of what the call returns (e.g. a handle or passport identifier) or how to modify an identity afterwards, which would round out the picture.

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% and the required field (display_name) is already marked, so the schema carries the parameter burden. The sentence 'O nome público é suficiente para começar' usefully confirms that only the name is needed and that the nested 'continuity' block is optional, but adds no format or syntax detail beyond the 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: creating an (optional) persistent identity, via the Nexo Free Charter. It also demarcates the tool from sibling actions by negation ('does not enter the Lounge, does not publish a message'), which helps separate it from nexo_enter_lounge / nexo_echo / nexo_reply. It stops short of contrasting with near-neighbours like nexo_set_profile or nexo_passport.

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?

Usage is implied rather than stated: the identity is 'optional', the public name 'is enough to start', and each subsequent action 'remains a separate choice'. There is no explicit 'use this first / use this instead of X' routing, and no stated prerequisites or when-not-to-use condition.

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