Restore Previous App

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

Beyond the annotations (readOnly=false, destructive=false), it discloses that the destination is re-observed and old screenshots/refs are not restored, warning the agent not to rely on stale UI state. It does not mention failure modes, but the added behavior is material.

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 short sentences, with the core behavior first and the behavioral caveat second. No filler or schema repetition.

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-request navigation tool, the description covers purpose, timing, and a key behavioral nuance, and the sibling list provides surrounding context. It could optionally address the no-previous-app case or return value, but these are not critical for invoking it.

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 only parameter (device) is already fully described in the schema, including how to discover valid values. The tool description adds no parameter-specific detail, so the schema-coverage baseline 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 action ('Return to the app') and precisely scopes the target as the one foreground before the last verified app launch or app-link session. This clearly distinguishes it from sibling launch/app-resolution tools and is not a tautology.

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?

Conveys the usage context (after a verified launch or app-link session) and implies it is a backtracking operation. It does not explicitly name alternatives or exclusions, so it falls 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.