List test layers

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

No annotations are provided, so the description carries the behavioral burden. It does disclose that custom YAML layers are merged in, which is useful, but it does not describe return format, pagination, error behavior, or whether any side effects occur. For a simple list operation, this is adequate but not rich.

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 with no filler. The core action and layer types are front-loaded, and the custom YAML merge behavior is an important extra detail that earns its place.

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 tool with one optional parameter and no output schema, the description is nearly complete. It names the resource, enumerates the layer types, and notes the YAML merge behavior. It lacks only explicit guidance on when to choose this over sibling tools, which is a minor gap for such a simple listing operation.

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 single parameter cwd already has a complete description in the input schema ('Directory used to load automation-coverage.yaml'), so schema coverage is 100%. The tool description adds no additional parameter meaning but does not need to, given the schema is sufficient.

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 specific verb ('List') and resource ('pluggable test layers'), enumerating the exact layer types: unit, integration, component, UI/Playwright, smoke, and cluster. It also notes that custom YAML layers are merged, which distinguishes it from simpler listing tools and siblings like get_coverage or inventory_tests.

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?

No explicit guidance is given on when to use this tool versus alternatives such as inventory_tests or generate_layer_brief. The context is clear that it lists layers, but there are no exclusions, prerequisites, or sibling comparisons to help an agent select it confidently.

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