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

readOnlyHint=true already declares a safe read operation, so the safety profile is covered. The description usefully adds the shape of the returned payload and the underlying endpoint (GET /api/v2/agents), but says nothing about pagination behavior, default page size, or result ordering — the main behavioral gaps for a list endpoint.

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?

One compact sentence plus a short endpoint reference; the resource, return fields, and purpose are front-loaded with zero filler. Every clause earns its place.

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?

With no output schema, listing the return fields is exactly the right compensation, and annotations carry the read-only safety profile. The only shortfall is that a caller wanting 'all agents' gets no hint that results are paged by default, which matters for a list tool used to pick an assignee.

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%: page, count, and the online tri-state filter (1/0/-1) are all documented in the schema itself. The description's mention of 'online state' loosely echoes the filter but adds no syntax, value semantics, or defaults beyond what the schema provides.

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?

The description states a specific verb and resource ('List the helpdesk's agents') and enumerates the returned fields (id, name, email, online state), which cleanly distinguishes it from siblings like deskpro_list_people or deskpro_list_departments. An agent can identify what this tool returns without opening the schema.

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?

'needed to assign a ticket' gives a concrete triggering context, which is more than most list tools offer. It stops short of naming when-not-to-use or an alternative (e.g., deskpro_search for finding a specific agent), so it isn't a full 5.

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