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

Annotations already declare readOnlyHint=true, openWorldHint=false and destructiveHint=false, so the safety profile is covered. The description adds genuine behavioral context beyond that: fields searched, the two-word firstname+lastname rule, and the important constraint that results are capped and de-duplicated by name with a recommendation to narrow the query. It stops short of describing pagination or ordering, so a 4 rather than a 5.

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?

Front-loads the purpose in one sentence, then uses a short bulleted usage block and a final paragraph on search semantics. Every sentence carries information, though the bullet list format is slightly more fragmented than a tight prose description would be.

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?

An output schema exists so return values need no explanation, and the description covers the remaining agent-relevant questions: what is searched, how multi-word queries are interpreted, why results may be missing (capping/de-duplication), and what to do about it. Complete for a read-only lookup tool with full schema coverage.

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% – both 'query' and 'limit' are fully documented in the schema, including the min-3-character rule, case-insensitivity and the 25 cap. The description restates much of the same matching semantics rather than adding new syntax or format guidance, so the baseline 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 ('Search the account's document users') and immediately scopes it with a parenthetical definition that separates document users (people with access to documents) from the account users and external parties covered by sibling tools like list-account-users and find-external-parties.

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?

Has an explicit 'Use this tool when:' block naming two concrete triggers (needing a name to filter list-documents by document user, and searching for matching document users), which names the downstream tool the results feed into. Nothing about when to reach for this versus the other find/list siblings is left to inference.

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