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

With no annotations provided, the description carries the full burden of behavioral disclosure. It does disclose key returns (created user and access_token) and the side effect of registering a client app when `client_url` is supplied, including that app name/icon are fetched via OpenGraph. However, it omits critical behavioral details for a mutation tool: whether this requires authentication, what happens on duplicate username/email, password constraints, and whether registration is reversible. This is a moderate but incomplete disclosure.

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 two sentences, front-loaded with the primary action and return values, then a secondary conditional behavior. It is efficient and avoids repetition. Slightly more could be trimmed, but it earns its place by covering both the core action and the optional client registration.

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 a 4-parameter mutation tool with no annotations, no output schema, and 0% schema description coverage, the description is only partially complete. It explains the return values and one optional parameter's behavior, but does not cover authentication requirements, error cases, or constraints on required fields (`username`, `password`). An agent could invoke it but would lack context for robust use.

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%, so the schema itself provides only parameter names and types. The description adds meaning for `client_url` by explaining its purpose (registering the client app and fetching OpenGraph metadata) but says nothing about `username`, `password`, or `email` — no formats, constraints, or validation rules. It partially compensates for the low schema coverage but leaves three of four parameters undocumented in natural language.

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 specific verb and resource — 'Crée un nouveau compte utilisateur' (creates a new user account) — and adds a secondary behavior (returns the user plus an access_token, and optionally registers a client app). This distinguishes it from sibling tools like mcp_login (which presumably authenticates an existing user) and mcp_create_* tools for other resources. It is clear but does not explicitly differentiate itself from mcp_login or mcp_create_community.

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?

The description implies when to use it (to create a new account) and explains an optional behavior when `client_url` is provided, but it does not explicitly state when to use this tool vs alternatives such as mcp_login or mcp_update_user. No exclusions or prerequisites (e.g., 'use this only if you don't already have an account') are given, leaving the agent to infer usage context.

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