Build app

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

With no annotations provided, the description carries the full burden. It discloses key behavioral traits: on failure, it returns compact compiler errors with file:line format, and on success, it returns the APK path. This goes beyond a simple tautology by explaining the output format. However, it does not mention side effects like modifying the build directory or the length of the operation.

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 concise at just two sentences. The first sentence front-loads the core purpose, and the second sentence succinctly covers both success and failure outcomes. No unnecessary words or 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?

The description is fairly complete for a build tool. It states the build mechanism, success/failure return values, and the tool's scope. The schema handles parameter details. It does not mention potential prerequisites (e.g., project setup) or performance characteristics, but these are not critical for a standard build operation. The presence of sibling tools like clean and get_apk_path does not reduce the completeness of this tool's description.

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 schema covers 100% of the parameters with descriptions, so the baseline is 3. The description does not add any parameter-specific details beyond the schema. It mentions 'assemble<Variant>' but does not elaborate on the module, variant, or projectDir parameters, leaving the schema to carry the explanatory weight.

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's action: 'Build an APK with Gradle (assemble<Variant>)'. It specifies the exact Gradle task pattern and differentiates from sibling tools like build_run (which implies building and running) and get_apk_path (which retrieves the path). The verb 'build' and resource 'APK' are precise.

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 the tool is used to build an APK, but it does not explicitly state when to use this tool versus alternatives. No exclusions or alternative tool mentions are provided. Since the purpose is clear, the usage is implied rather than explicitly guided.

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