Deep Link into an App

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

The description says 'Launch an app' which implies a write/mutation operation, but the annotation readOnlyHint=true indicates this is a read-only operation. This is a clear contradiction. The description does not disclose any other behavioral traits beyond what annotations already provide.

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?

The description is two sentences long, directly states the purpose, and provides an equivalent API call with no wasted words. It is well-structured and concise.

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 4 parameters, 50% schema description coverage, and no output schema, the description is too brief. It does not cover parameter details for appId and device, nor does it describe the return state or side effects. The contradiction with annotations further reduces completeness.

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 description adds meaning for contentId and mediaType, but the required appId parameter and the device parameter are not explained. With schema description coverage at 50%, the description partially compensates but leaves gaps.

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 clearly states the tool launches an app with a deep link using contentId and mediaType. It provides an equivalent ECP endpoint, making the purpose specific. However, it does not explicitly differentiate from the sibling tool launch_app, which might serve a similar function.

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 implies usage for deep linking via the mention of contentId and mediaType and the ECP equivalent. However, it lacks explicit guidance on when to use this tool versus alternatives like launch_app, and does not state prerequisites or limitations.

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