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

readOnlyHint=true already establishes the safe-read profile, so the bar is lower. The description adds the return shape (id, name, email) — valuable since there is no output schema — plus the underlying REST call (POST /users/search), which explains why a read maps to a POST endpoint. It says nothing about rate limits or the pagination default, but the schema covers pagination.

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?

A single front-loaded sentence covering purpose, payload, and use case, followed by a short endpoint reference. No filler or repetition.

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-param, paginated list tool with no output schema, the description supplies the essential return fields and the when-to-use rationale. It is nearly complete; only total-count or ordering behavior is left unspecified.

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%, so both page_size and page_number are already fully documented with defaults and bounds. The description adds no parameter meaning beyond listing returned fields, which is the expected baseline when the schema does the work.

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 (List) and resource (users in the Copper account), and enumerates the returned fields (id, name, email). This cleanly distinguishes it from the many sibling list/search tools that target other resources (activities, pipelines, people, companies).

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?

"useful for resolving assignee ids" gives a concrete when-to-use scenario, which is exactly the agent's decision context. However, it names no alternative tool or exclusion condition, so it falls short of a full when/when-not statement.

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