n8n: Add project users

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

Annotations already declare destructiveHint=true and idempotentHint=false, so the agent knows this is a mutating, non-idempotent operation. The description adds the licensing gate, which annotations do not cover. It does not explain what happens if a listed user is already a project member (duplicate, overwrite role, or error) or whether any existing membership data is lost, which matters given destructiveHint=true.

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?

Two compact, front-loaded sentences with no filler. The bracketed [UNIFIED] tag is boilerplate noise but small, and the licensing requirement follows immediately.

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?

For a destructive, non-idempotent write tool with three required params at 0% schema coverage and no output schema, this is too thin. The shape of the users array (what keys map to roles) and the meaning of "site" and "project_id" are all left undefined, so the agent cannot reliably construct a valid call.

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% and the description compensates only partially: "users" and "with roles" hint that the users array carries role assignments, but the array items schema is an untyped empty object and the required "site" and "project_id" parameters are nowhere explained. With three required params and no schema documentation, the description leaves the caller guessing at structure.

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 ("Add users to a project") plus the qualifier "with roles", which separates it from n8n_remove_project_user and n8n_change_project_user_role. It never names those siblings explicitly, so differentiation is implied rather than stated.

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 a real prerequisite (an n8n Enterprise/Pro license must be active) which will gate usage. It gives no guidance on when to use this batch operation versus the single-user role-change tool, and no exclusions or failure conditions.

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