List apps

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

Annotations include readOnlyHint and openWorldHint, so the safety profile is already established. The description adds valuable context: the App Store side is auto-discovered while the Play side relies on PLAY_PACKAGES, explaining why the output set may vary by configuration. This goes beyond the annotations without contradicting them.

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 concise sentences. The first states the core purpose, the second explains the mechanism/limitation. No redundancy, and the key information 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?

The tool is simple (one optional param) and has an output schema, so no return-format explanation is needed. The description covers what apps are included, the dependency on credentials, and the Play-side caveat, which is sufficient for an agent to decide when to call 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?

Schema coverage is 100% with a clear description of the 'store' parameter and its default. The tool description does not add any additional parameter semantics beyond restating the store sources, so baseline 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?

The description clearly states the tool lists all apps reachable with credentials from both stores, which is a specific verb+resource scope. It distinguishes implicitly from siblings like get_app and get_releases by focusing on enumeration, but does not explicitly name alternatives, so it stops short of a 5.

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 this is the tool to enumerate apps, and notes the limitation of Play discovery, but it does not explicitly state when to use it versus alternatives or provide any exclusions. Usage context is inferable from the name and scope but not spelled out.

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