Compare rooms

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

Annotations already declare readOnly, idempotent, non-destructive, so the safety profile is fully covered. The description adds that output consists of per-room metrics plus rankings, but says nothing about prerequisites (rooms actually having thermostats/valves), data gaps, or cost of a 30-day window. Useful framing, no deeper behavioral disclosure.

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 sentences, no filler. The core action and the default window are front-loaded, followed by the concrete metric list and the return shape.

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 full schema coverage, a present output schema, and read-only annotations, the description carries the remaining burden well by naming the derived metrics and rankings. It could still mention that rooms lacking thermostat data are omitted or reported as insufficient, which matters for interpreting a comparison across all rooms.

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%, so the baseline is 3, but the description contributes something the schema does not state: that the default period is the last 7 days. It still adds nothing about the from/to vs period interaction or home_id resolution beyond the schema text.

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 ('Compare all rooms over a period') and then enumerates the exact comparisons produced: warmest/coolest, most variable, most time below target, largest drop, fastest cool-down. This cross-room ranking scope cleanly separates it from the single-room status tools and the home-level heating summary siblings.

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?

The description makes clear the tool is for period-based cross-room comparison and discloses the default window (last 7 days), which tells an agent when it is safe to call with no time arguments. It does not explicitly say when to prefer a sibling (e.g. netatmo_get_temperature_history for one room), so there is no exclusion guidance, but usage context is unambiguous.

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