List devices

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

Annotations already declare readOnlyHint, idempotentHint and non-destructive behavior, so the safety profile is covered. The description adds value by stating the content of the result set (model, room, gateway) and by carving off status-type data to a sibling. It does not mention auth or rate-limit behavior, but those gaps are minor given the annotation coverage and the existing output schema.

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 scope statement is front-loaded and the sibling routing follows immediately, which is the correct order for an agent scanning for selection signals.

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 one-optional-parameter read tool with a rich annotation set and an output schema, the description supplies everything an agent needs: what comes back, the scope of the listing, and where to go for adjacent data.

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% and the single parameter is fully documented in the schema, including the 'optional when the account has a single home' rule. The description's phrase 'of a home' echoes rather than extends that, so the 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?

Names a specific verb ('List') and enumerates exactly which resources are returned (thermostats, radiator valves, relays/gateways) plus the fields attached to each. This distinguishes it cleanly from netatmo_get_device_status, which the description explicitly routes elsewhere.

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?

Explicitly names the alternative (netatmo_get_device_status) and the condition that selects it: battery, signal and reachability queries. The scope 'of a home' combined with the schema's note that home_id is optional for single-home accounts leaves little inference required.

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