Validate CAP (cds compile)

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

No annotations are provided, so the description carries the burden. It discloses that the tool runs cds compile and returns errors, and frames it as a non-mutating validation operation ('A clean compile means the scaffolding is valid'). It doesn't detail what happens to the project, whether cds compile has side effects, or what the error format looks like, but the read-only validation nature is reasonably clear.

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?

Three sentences, tightly written, no filler. The opening 'The validation loop' sets framing, and the second sentence explains the concrete action. Every sentence serves a purpose, though slightly repetitive between the two opening sentences.

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?

With only one parameter (fully covered by schema), no output schema, and no annotations, the description is fairly complete for a simple validation tool. It explains purpose, outcome interpretation (clean compile = valid), and the fixing loop. Gaps: no mention of sibling cap_lint differentiation and no detail on error format. For a low-complexity tool with 1 well-documented param, this is adequate but not rich.

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 100%, so the parameter projectPath is fully documented in the schema ('CAP project root path with @sap/cds available'). The description adds the behavioral nuance that the compile requires @sap/cds availability, which the schema already notes. The description doesn't add meaning beyond the schema, so baseline 3 is appropriate.

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 what the tool does: 'Runs cds compile on the project and returns the errors so the agent can fix them.' It identifies a specific verb (runs/validate), resource (CAP project/compile), and purpose (validation loop). It distinguishes from siblings like cap_scaffold_entity or cap_lint through the compile/validation purpose, though it doesn't explicitly name difference from cap_lint.

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 usage in a validation loop during scaffolding work ('The validation loop. Runs cds compile... so the agent can fix them'). It says a clean compile means scaffolding is valid, giving context on when it's needed. However, it doesn't explicitly say when NOT to use it or name alternative validation tools like cap_lint, which could overlap.

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