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

With no annotations, the description carries full responsibility and does well: it discloses the control-channel-first strategy, the fallback to `cmd statusbar` shell, and the exact return tuple {ok, action, transport}. It also warns about OEM variation, which is exactly the kind of non-obvious behavior an agent needs.

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 tight sentences cover the operation, per-action behavior, fallback mechanism, and return shape. Every clause earns its place and the most important usage distinction is front-loaded.

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 two-parameter tool with no output schema, this is complete: action semantics, OEM caveat, fallback path, and return structure are all specified. There are no mysterious failure modes left for the agent to guess.

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?

Although the schema already lists the action enum and UDID, the description adds real semantics for every action value: what 'notifications' means, what 'settings' may require, and what 'collapse' does. This goes well beyond the schema's generic 'Which panel operation to perform'.

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 precise verb and object ('Pull down the notification panel, the Quick Settings panel, or collapse open panels') and then enumerates each action value with concrete semantics. This is clearly distinguishable from nearby siblings like device_notifications because the action enum maps to distinct UI operations.

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 gives action-specific operational guidance, including the OEM caveat that Quick Settings may require opening notifications first. It doesn't explicitly state when not to use this tool versus a swipe/gesture alternative, but no obvious sibling offers the same behavior, so the guidance is sufficient.

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