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

The readOnlyHint annotation already establishes the safety profile, so the bar is lower. The description adds that retrieval is backed by POST /users/search, which is genuinely non-obvious for a "list" operation, but says nothing about result caps, pagination totals, or permissions.

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 carrying purpose, returned fields, and use case, plus one short line of endpoint metadata. Nothing is padded, though the REST endpoint note is marginally useful at best.

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?

This is a simple paginated read with no output schema, so the description's enumeration of returned fields usefully compensates. Pagination behavior is fully covered by the schema, leaving only permissions and total-count semantics unstated.

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 100% with both page_size and page_number fully documented including defaults and max values, so the baseline of 3 applies. The description mentions only returned fields, adding nothing beyond the schema on parameters.

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 users in the Copper account"), names the returned fields (id, name, email), and gives the tool's role: resolving assignee ids. No other sibling tool operates on users, so there is no ambiguity to resolve.

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 use context, which is more than most list tools offer. It stops short of stating when not to use it or naming an alternative source of user data, but no sibling overlaps this function.

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