set_color

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

With no annotations, the description carries full burden. It discloses that the tool switches the light to color mode. However, it does not mention potential side effects (e.g., overriding previous color, whether it turns on the light if off) or any permissions or rate limits.

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 very concise: 4 sentences plus an Args section. It front-loads the main action, distinguishes from a sibling, and lists parameters with clear semantics. No unnecessary words.

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 the tool's simplicity and the presence of an output schema (not shown), the description covers purpose, usage distinction, parameter semantics, and address guidance. It does not mention return values (not needed due to output schema), but could add a note about the light's state (e.g., whether it turns on automatically).

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 0%, but the description adds full semantic meaning: red, green, blue are RGB values 0–255; address is a Bluetooth address from scan_hue_lights or the HUE_LIGHT_ADDRESS env var. This compensates entirely for the missing schema descriptions.

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 clearly states it sets the color of a Philips Hue light using RGB values, and explicitly distinguishes from the sibling tool set_color_temperature by noting that it switches to color mode and that set_color_temperature returns to white mode.

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 tells when to use this tool (to set color) and when to use set_color_temperature instead. It also provides guidance on the address parameter, referencing scan_hue_lights. However, it does not mention prerequisites like the light being on or other context-specific conditions.

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