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

Annotations already flag this as non-read-only and non-destructive; the description usefully explains the interaction mechanism (swipe up), which is real context beyond the annotations. It does not say whether the call fails, no-ops, or succeeds silently when no panel is open, nor how it interacts with overlays such as open dialogs.

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?

One sentence, front-loaded with the verb and the targets, with the mechanism in parentheses. No wasted wording or redundant restatement of the tool name.

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 single-parameter UI-gesture tool with no output schema, the description covers what is acted on and how, and the annotations cover the safety profile. Nothing an agent needs in order to invoke it correctly is missing.

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?

There is a single parameter and schema description coverage is 100% ('Session from open_app' is documented in the schema). The description adds no additional meaning about the session value, so the baseline of 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 ('Close') with concrete resources (notification shade, Notification Center, Control Center) and even the gesture used ('swipe up'). This clearly separates it from siblings like open_control_center and open_notifications, which open rather than dismiss panels.

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?

Usage is only implied: an agent infers it should call this when a shade or center is open and needs dismissing. There is no explicit when-to-use framing, no mention of what happens if no panel is open, and no pointer to alternatives such as back for general dismissal.

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