compile_shader

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

With no annotations, the description carries the full burden and handles it well: it discloses the output file location, write confinement to download root or BIONIC_PROJECT_ROOTS, automatic glslangValidator fallback, and error reporting with file and line. It could mention overwrite behavior, but this is strong disclosure.

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 purpose is front-loaded, and the extension-to-compiler rules are organized in a scannable bulleted list. Every sentence conveys necessary information without filler.

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 tool's complexity, the description covers compiler selection, required flags, fallback behavior, output location, and write confinement. An output schema exists, so return values do not need elaboration. The only significant gap is the undocumented `working_directory` parameter.

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 description coverage is 0%, so the description must compensate. It explains source extension behavior, `stage`, `profile`, `spirv`, and `output`. However, `working_directory` is never mentioned or explained, leaving one of six parameters undocumented.

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 opens with a specific verb and resource: 'Compile a shader and report errors with file and line.' The extension-to-compiler mapping makes it unmistakably a shader compilation tool and separates it from sibling file and project tools like build_project.

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?

It provides clear parameter-level usage conditions: .glsl requires `stage`, .hlsl and .fx require `profile`, and `spirv=true` changes the target. It does not explicitly say when to prefer this tool over build_project, so it stops short of full when/when-not guidance.

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