fleet_utilization

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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds value beyond that by characterizing the payload as a 'lightweight overview' and naming the exact metrics returned, which tells the agent this is a cheap summary call rather than a detailed dump. It does not mention refresh cadence or whether counts are live, so it falls short of 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?

Three short sentences, front-loaded with the purpose and metric list, followed by two routing pointers. Every sentence carries distinct information; nothing is redundant with the title or annotations.

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 and zero parameters, the description must carry the return-value burden, and it does by naming the counts and utilization percentage. The only gap is that it does not describe the shape of the response (flat counts vs. per-site breakdown), which matters given siblings like fleet_status_by_site, but overall it is sufficient to call correctly.

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 no parameters, so there is nothing for the description to disambiguate — the baseline of 4 applies. The schema is an empty object and the description correctly implies no inputs are required.

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 (get fleet utilization metrics) and then enumerates the concrete outputs — busy/idle/offline counts and utilization %. It explicitly names the two nearest siblings (fleet_status for full printer details, fleet_analytics for history), so an agent can separate it from those without opening any 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?

Gives explicit routing: use this for a lightweight capacity overview, use fleet_status for full printer details, and fleet_analytics for historical analytics. That is a when-to-use plus two named alternatives with the conditions that select them, leaving nothing to inference.

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