timegate_set_brightness

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

No annotations, so the description carries the full load. It usefully discloses that the setting is global across the five independent 128×128 screens, but says nothing about persistence, what brightness 0 does (screen off vs. dim), required token/auth, or discovery/timeout behavior during the call.

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?

Three compact clauses with the core action front-loaded and no filler; the hardware qualifier and guide pointer follow in logical order. The 'five independent 128×128 screens' fragment is slightly telegraphic but still informative.

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, no output schema, a nested target object and a required localToken, the description covers the device scope but leaves mutation side effects, token requirement, and target-override behavior entirely to the schema. Enough to call it, not enough to call it confidently.

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?

The 0–100 range is already enforced by the schema's minimum/maximum, so restating it adds nothing, and the description says nothing about target/model/hardware selection or when localToken is needed. Schema coverage is 67%, which is adequate, so 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 and resource (set global LCD brightness) plus the value domain (0–100), and immediately scopes it to TimeGate Hardware 400/402, which cleanly separates it from the sibling pixoo64_set_brightness and watchface_set_brightness.

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 hardware restriction ('TimeGate Hardware 400/402 only') tells the agent when this tool applies and implicitly rules it out for PIXOO64/other devices, and it routes to divoom://timegate/guide for more detail. No explicit negative case or named alternative tool, so just short of a 5.

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