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

readOnlyHint=true already tells the agent this is a safe read, so the description's added value is the shape of the result (id, name, email, online state) and the underlying endpoint GET /api/v2/agents. That field disclosure is genuinely useful given there is no output schema, though pagination/filter behavior is left to the schema.

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 delivers purpose, payload, and use case, with the API endpoint appended compactly. No filler or redundancy.

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 zero-required-parameter read-only list tool, the definition covers purpose, use case, and returned fields, and the schema covers all inputs. Without an output schema the field list compensates well, though pagination behavior on the response side is only implied by the input parameters.

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 page, count, and online all fully documented including the -1/0/1 semantics of online. The description adds nothing beyond that, so the baseline 3 is correct — the schema carries parameter meaning entirely.

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 the helpdesk's agents') and immediately names the returned fields (id, name, email, online state), which separates it from siblings like deskpro_list_people and deskpro_list_organizations. The stated purpose (assigning a ticket) sharpens the distinction further.

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 context for use — 'needed to assign a ticket' — which tells the agent when this tool is relevant. It does not, however, name an alternative or a when-not condition (e.g., use list_people for end-users), so it stops short of full routing guidance.

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