Launch And Ready

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

Annotations already provide readOnlyHint=false and destructiveHint=false, and the description adds useful behavioral detail: it waits for confirmation of readiness and returns a frame-validated screenshot. It does not mention the cold-mode force-stop behavior in the description itself, but this is disclosed in the schema and does not contradict the annotations.

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 dense sentences with no filler. The primary behavior is front-loaded, and the second sentence adds strategic usage guidance without redundancy.

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?

Given the complex 8-parameter schema and no output schema, the description explains the core contract well: launch, wait, screenshot. It could be more explicit about the return format of the screenshot or readiness semantics, but the description gives enough for an agent to select and invoke the tool correctly.

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 all eight parameters including the nested waitFor object are already documented. The tool description adds no parameter-specific meaning, so the baseline of 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?

The description names a specific action sequence: launch an app, wait until ready, and return a fresh frame-validated screenshot. It clearly differentiates itself from siblings like mobile_launch_app or mobile_wait_for_app by framing this as a single combined entry point.

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 phrase 'preferred one-call app entry point for agents' gives clear usage context, telling the agent to prefer this over multi-step alternatives. It does not, however, specify when NOT to use it or name explicit alternative tools for partial workflows.

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