get_expansion_file

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

With no annotations, the description carries the full burden. It discloses the return fields (fileSize, referencesVersion) and an error condition (for app bundles). It implies read-only via 'Get' and provides important context about legacy vs modern app distribution, though it does not mention authentication, rate limits, or other side effects.

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 action and return values, the second adds usage caveat. No wasted words, front-loaded with the critical purpose. Excellent structure.

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 simple getter with no output schema, the description sufficiently explains what is returned, when it errors, and its legacy nature. All parameters are documented in the schema, and the description fills in the only missing context (the bundle caveat). It is complete given the tool's simplicity.

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 input schema covers all 3 parameters with clear descriptions (package_name, apk_version_code, expansion_file_type), so baseline is 3. The tool description does not add extra parameter-level detail beyond the schema, though it does provide domain context about legacy APKs that might influence how parameters are used.

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 uses a clear verb 'Get' and specifies the resource 'OBB expansion file attached to an APK version code', also stating the return values (fileSize and referencesVersion). It is specific and distinct from sibling tools, which focus on tracks, releases, reviews, etc.

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 explicitly notes this is a 'Legacy APK-only feature' and that apps using app bundles will 'get an error here', effectively telling agents when not to use it. However, it does not name an alternative sibling tool, only mentions 'asset packs' conceptually, so it lacks a direct alternative reference.

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