set_accessory

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

With no annotations, the description carries the behavioral burden. It discloses that this is a mutating control action and gives representative effects, but it does not mention error behavior, persistence, reversibility, or side effects beyond the value change.

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 short sentences: the first states the main function and examples, the second gives the critical prerequisite. Every sentence earns its place, with no filler or repetition of the schema.

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 mutation tool with no annotations and no output schema, it adequately explains how to obtain inputs and what to set. It does not describe the return value or failure cases, leaving some operational context unspecified.

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% and each parameter already has a meaningful description. The tool description adds no new parameter semantics beyond reinforcing the characteristicType examples, so the baseline of 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?

The description uses a clear verb ('Control') with a specific resource ('Homebridge accessory') and lists concrete example operations (on/off, brightness, color temperature). It is easily distinguished from sibling get_accessory and listing tools, so an agent can identify when to use it.

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?

It gives an explicit prerequisite and tells the agent exactly what to look up first: uniqueId and characteristicTypes via list_accessories. It does not explicitly state exclusions or when to prefer get_accessory for reads, so it falls just short of full routing guidance.

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