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

The readOnlyHint annotation already establishes safety, and the description adds the non-obvious behavioral detail that each user's API key is redacted from the result. It also lists the visible returned fields and the underlying GET endpoint, though it does not mention pagination or auth requirements.

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 tightly written sentences front-load the resource and returned fields, then add the important redaction behavior, and finally identify the endpoint. Every element earns its place 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?

For a simple read-only list operation with no parameters, an empty schema, and no output schema, the description supplies the return fields and the API-key redaction detail. Nothing essential for correct invocation appears to be missing.

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 tool takes zero parameters, so there is no parameter semantics for the description to clarify. The empty schema and zero-parameter baseline make 4 the appropriate score.

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: listing the account's users, and it enumerates the returned fields (name, email, timezone, company, owner/admin flags, permissions). No sibling tool covers user listing, so the purpose is immediately distinguishable from form, report, entry, and webhook tools.

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 by the operation itself, but the description provides no explicit when-to-use guidance, prerequisites, or alternatives. For a simple read-only list endpoint this is minimally adequate, though an agent must infer that it is the only user-listing tool.

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