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

readOnlyHint=true already tells the agent this is a safe read with no side effects, so the description carries a lighter burden. It adds the REST endpoint (GET /users), which is mildly useful for traceability, but discloses nothing about pagination limits, rate limiting, or scope of visibility beyond the annotations.

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 sentences: the first states what is returned, the second states why to call it. The endpoint reference is a short trailing clause. Nothing is padded or redundant.

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 two-parameter read-only list with no output schema, the description covers purpose, returned fields, and intended use well enough to invoke correctly. Minor gaps remain around pagination behavior and visibility scope, which the annotations and schema don't cover either.

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 100% – pageToken and maxResults are both fully documented in the schema, including the 1-50 range and default of 10. The description adds no parameter-level meaning, so the baseline of 3 applies.

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 ('List workspace users') and enumerates the returned fields (id, email, name, role), which is more than a bare restatement. It does not explicitly contrast itself with siblings like openphone_list_contacts, but the resource is unambiguous enough that an agent won't confuse the two.

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?

Gives a clear reason to call it: 'Use to find a userId for scoping other calls.' This is a genuine usage context rather than an implied one. It lacks any when-not guidance or named alternative, so it stops short of a 5.

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