timegate_get_brightness

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

With no annotations, the description carries the full load and does well: it discloses which internal channel is used per hardware revision, warns that the reference Sys/GetBrightness endpoint returns a hardcoded 100 and is not used, and explains that effective brightness reads 0 while the screen is off. It omits the LocalToken authorization requirement, which lives only in the schema.

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?

Five short sentences, each carrying distinct information: verb, per-model read path, a negative fact about the reference API, the screen-off edge case, and the hardware/resource pointer. The core action is front-loaded and nothing is repeated.

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?

No output schema exists, and the description covers the key return-value nuance (0 when the screen is off) plus device-family limits, which is what an agent needs to interpret the result. It could be slightly more explicit about the return shape or the auth prerequisite, but the essentials are present.

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 the target override and LocalToken are already fully documented in the schema. The description adds only the hardware 400/402 constraint, which the schema's hardware enum already conveys. Baseline 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?

Opens with a specific verb+resource ("Read brightness") and immediately scopes it to TimeGate Hardware 400/402, which separates it from the watchface_* and pixoo64_* brightness siblings. It never names the alternative tool for other hardware, so the sibling differentiation is implicit rather than explicit.

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?

Clear context for when this applies: 400 vs 402 read paths, TimeGate-only hardware, and a pointer to divoom://timegate/guide for deeper detail. It does not state the inverse (use timegate_set_brightness to change the value) or what to do on other hardware models, so it stops short of full when/when-not guidance.

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