device_list

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

No annotations are provided, so the description carries the burden of behavioral disclosure. It does indicate a read-only lookup operation and enumerates the included output fields, which is useful. However, it does not mention pagination, ordering, auth requirements beyond login visibility, or any side effects, leaving the behavioral picture incomplete.

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?

The description is a single sentence plus a compact parenthetical field list. Every word adds value: the operation, the account scope, and the important returned data are all present with no filler or repetition.

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?

Given that the tool has no parameters and no output schema, the field list in the description provides most of what an agent needs to know about the return value. It could be more complete with notes about ordering, pagination, or what the listed fields mean, but it is sufficient for a first call.

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 has zero parameters and the input schema has no properties, so schema coverage is effectively complete. The description has no parameter obligations, and it instead uses the space to describe output fields, which 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?

The description states a specific operation—list measuring instruments—and gives the scope: devices visible to the logged-in account. It also lists the returned fields, which clarifies what kind of device list this is. It does not explicitly contrast with siblings like device_get or site_list, so it stops short of full sibling differentiation.

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 phrase 'devices visible to the logged-in account' provides clear context for when to call this tool: you need the account-scoped device list, not a single device or live stream. It does not mention alternatives or exclusive conditions, so it lacks the explicit when-not-to-use guidance that would earn a 5.

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