downtime_pareto

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

Annotations only declare readOnlyHint, so the description carries most of the behavioral load and does it well: default exclusion of planned maintenance, largest-first ordering, cumulative share output, and the meaning of the `vital_few` grouping. It stops short of mentioning aggregation window or empty-result behavior, so not 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?

Two tight sentences; the primary behavior (ranked downtime with cumulative share) leads, and the one notable default (planned maintenance excluded) follows. No filler or restated field names.

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 an output schema present, return values need not be explained, and the description supplies the default-exclusion rule and the vital_few semantics an agent needs to interpret results. Only the filter parameters' interactions (line/machine/date range together) go unaddressed.

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 coverate is 67% and the description touches only `include_planned` ('unless asked') and implies a top-N cutoff via vital_few. It says nothing about `top` (default 10, max 20), `line`, `machine_id`, or the date range semantics, so it adds little beyond the documented schema fields. Baseline 3 is appropriate.

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+resource ('Downtime by reason') and the exact output shape: sorted descending with share and cumulative share. The reference to pareto/vital_few makes it unambiguous that this is an analysis tool rather than a raw event list like downtime_events.

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 one scoping rule ('Planned maintenance is excluded unless asked') which shapes when the tool is appropriate, but never contrasts it with siblings such as downtime_events or machine_oee, nor states when a Pareto view beats a plain event listing. Usage is implied rather than guided.

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