update_device_custom_property

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

The description adds behavioral context beyond annotations: it notes the requirement for propertyType to match the definition and lists valid types, which aids correct invocation. Annotations already indicate non-read-only, non-destructive, open-world behavior, so no contradiction.

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 fluff. First sentence states purpose; second provides critical usage details. Perfectly efficient.

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?

The description adequately covers the tool's purpose and requirements. No output schema exists, but the simplicity of the operation and the availability of 'get_device_custom_property' as a companion tool make the description sufficient for an agent.

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?

With 100% schema coverage, baseline is 3. The description adds practical guidance: emphasizing that propertyName and propertyType must match existing definitions, and hints at enumeratedValueList for ENUMERATED type, providing extra meaning.

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 'Update a custom property value on a specific device.' This is a specific verb+resource, clearly distinguishing it from siblings like 'get_device_custom_property'.

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 explicitly advises to use 'get_device_custom_property' if unsure about existing values, providing an alternative tool and clear when-to-use guidance.

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