list_fleet_sites

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

The annotations already declare readOnlyHint, destructiveHint=false, and openWorldHint=false, so safety is covered without the description. What the description adds is meaningful: an Enterprise license prerequisite and the fact that the list is derived (distinct sites across registered printers) rather than a stored registry. It does not cover result ordering, empty-set behavior, or pagination, so a 3 is appropriate rather than higher.

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?

Four short sentences, front-loaded with the core action and the return content. There is minor redundancy ("fleet sites/locations" and "distinct sites defined across registered printers" restate the same idea) and baked-in multi-line indentation, but nothing is wasteful.

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-parameter, non-destructive read with no output schema, the description covers what it lists, how the list is derived, and the licensing gate. Only the shape of the returned per-site counts and behavior on a single-site or empty fleet are left 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?

The tool takes zero parameters, so there is nothing for the description to disambiguate and the baseline is 4. The description correctly does not invent filtering options, though it also never states that no filters are supported, which an agent might otherwise assume.

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 opens with a specific verb+resource ("List all fleet sites/locations") and adds the payload claim "with printer counts," then clarifies that results are derived from registered printers. This is clearly distinguishable from a status tool. It does not explicitly name the nearest siblings (fleet_status_by_site, update_printer_site), so it stops short of a 5.

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 multi-site fleet dashboards" implies the intended scenario, and the Enterprise license line is a real prerequisite that gates invocation. However, there is no explicit when-not guidance and no pointer to alternative tools for per-site status or site mutation, leaving the agent to infer selection.

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