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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds genuinely useful behavior not in the schema: result ordering ('newest first'). It says nothing about default page size, pagination envelope, or response shape beyond that.

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 tight sentences plus an endpoint reference; the capability statement is front-loaded and every clause carries information (scope, ordering, filter options, alternative tool, REST path).

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 read-only list tool with full schema coverage and no output schema, the description covers purpose, ordering, filtering, and tool routing. The main gap is lack of an explicit return-shape/pagination note, though the schema's limit/offset hints partially mitigate this.

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 all five parameters are already documented in-schema (ids, role enum, limit, offset, include expansion). The description only restates role and id filtering at a high level, adding no format or interaction detail beyond the schema, so 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 (list users), enumerates the four role types returned, and gives the ordering ('newest first') plus optional filters. It also names kayako_search as the different sibling, so an agent can distinguish this from get/search tools without opening schemas.

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?

Explicitly routes the agent: 'To find a user by email or name use kayako_search,' which is a concrete when-to-use-an-alternative rule. It lacks an explicit when-not for the id/role filters, so it falls short of full 5-level guidance.

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