start_music_mode

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

Annotations only state readOnlyHint=false and destructiveHint=false; the description adds that the mode reacts to audio playback and uses slow ethereal color. However, it omits session lifecycle details, such as that the mode continues until stopped via stop_music_mode, and it does not surface the default recording-for-training behavior that the schema mentions.

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 tightly written sentences with zero waste. The core behavior is front-loaded, and the mood list is appropriately appended as supporting detail.

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?

An output schema exists, so return values need not be explained. The description covers the mode's behavior and mood options; the main remaining gap is lifecycle information (how to stop it) and the privacy implication of recording, though the latter is documented in the schema.

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 description coverage is 100%, so both parameters are fully documented in the schema. The description repeats the available mood names but adds no selection guidance or interpretation beyond what the schema already provides, so the baseline 3 applies.

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?

States a specific verb ('start') and resource ('music mode') and explains the distinctive behavior: the light follows what the Mac is playing, including AirPlay from an iPhone. It is clearly distinguishable from static effect tools like set_effect, though it does not explicitly name siblings.

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 implies when to use it (when you want music-reactive lighting) but gives no explicit when-to-use/when-not guidance or alternatives. It does not mention stop_music_mode or explain how this differs from set_effect beyond the reactive behavior.

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