users_resolve

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

With no annotations, the description carries the full behavioral burden, yet it only states the lookup scope and parameter exclusivity. It does not disclose the return shape, behavior for unknown identifiers, error handling, or that this is a read-only operation.

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 a single sentence with the action and resource front-loaded, followed by a concise usage caveat. It contains no filler and does not repeat schema information.

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 simple three-parameter resolver, the description plus input schema provides enough information to invoke the tool correctly. The absence of an output schema and lack of return/error details is a minor gap, but it does not block correct usage.

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?

The schema already documents all three parameters with 100% coverage, and the description adds the critical constraint that exactly one identifier must be provided, which the optional parameters in the schema do not convey. This addition is valuable even though format details are not expanded.

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 names a clear action ('Resolve'), a specific resource ('a single user'), and the three accepted identifier types ('numeric ID, short UUID, or username'). This distinguishes it from broad list tools like users_list and from single-identifier siblings like users_get_by_username.

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 conveys that this is for single-user lookup and adds the important constraint 'provide exactly one'. However, it does not explicitly say when to prefer users_resolve over users_get, users_get_by_username, or users_get_by_short_uuid, so the usage guidance remains implied rather than explicit.

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