List custom sensors

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds no behavioral context beyond that — no mention of ordering, whether disabled sensors are included, whether it requires a configured controller connection, or anything about what comes back.

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?

One short parenthetical sentence with no waste, but it is a bare fragment that front-loads a resource definition rather than the action or return behavior.

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-param lister with no output schema and no annotation on return shape, the agent still lacks any idea of what a result entry looks like (name, id, type) or how many to expect. The definition of a custom sensor helps interpret results but does not fill that gap.

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?

Zero parameters, so there is nothing for the description to disambiguate; baseline 4 applies. Schema coverage is 100% on an empty object.

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 is a noun phrase that defines the resource ('user-defined custom sensors') but never states the action; the verb 'list' exists only in the tool name. The parenthetical distinguishing mixes-of-temps from file-based sensors adds real domain meaning, but the purpose statement itself is a fragment rather than a specific verb+resource claim.

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?

There is no guidance on when to call this versus alternatives such as list_devices or the create/update/delete custom sensor siblings. An agent must infer from the name alone that this is the read path for custom sensors.

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