users_update_user

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

No annotations are supplied, so the description carries the full behavioral burden, yet it discloses almost nothing: no permissions required, no note on whether omitted fields are preserved (the PATCH semantics are only implied by the URL line), no reversibility or side-effect information. The confirm-gating behavior exists only in the schema's 'confirm' property, not the description.

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 useful content ('Update a user by ID or username. Exactly one of the fields must be provided.') is buried after two boilerplate lines, one of which ('Tags: Users Controller') is pure noise. The PATCH line at least signals a partial-update semantics, but overall the structure wastes the prime opening slot.

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 mutation tool with no annotations, no output schema, and 50% parameter coverage, the description is under-specified: it never explains the confirm/preview mechanism, error behavior, or what a successful update returns. An agent has to fall back on the schema and Russian-language confirm text to call this safely.

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 coverage is only 50%, and the body holds 11+ properties while the description mentions only the id/username identification rule. It adds the useful 'exactly one identifier' constraint but leaves the bulk of updatable fields (status, expireAt, trafficLimit, squads, etc.) undiscussed, so it does not compensate for the coverage gap.

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 ('Update a user') and adds an identifying constraint ('by ID or username'), which distinguishes it from create/delete siblings. It does not, however, differentiate itself from bulk update siblings like users_bulk_actions_bulk_update_users, and the leading 'PATCH /api/users' line is raw HTTP boilerplate rather than purpose.

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?

'Exactly one of the fields must be provided' is a real usage constraint, but it is ambiguous about which fields and gives no guidance on when to prefer this over bulk update, enable/disable, or reset siblings. Usage is implied by 'update a user by ID or username' but no alternatives are named.

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