add_trace

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

With no annotations provided, the description carries the full burden and does well: it reveals critical behavioral traits such as unit normalization ('All distances are in millimetres'), the safe dry-run default, and the integrity check via expected_sha256. It goes beyond a generic 'add trace' statement by explaining the validation mechanism.

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 two sentences long, front-loaded with the primary purpose, and every clause adds value. It avoids repetition and effectively communicates the essential workflow in minimal space.

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 complex 11-parameter tool with no annotations, the description covers the critical usage context: preview-before-commit, expected_sha256 verification, and unit handling. It does not explain all parameter relationships or the structure of points, but the output schema and the focused safety workflow make the tool actionable enough.

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 has 0% top-level parameter descriptions, forcing the description to compensate. It adds meaning for dry_run and expected_sha256, and clarifies units for distance parameters. However, it does not explain the meaning or format of core parameters like net, start/end_object_id, points, layer, or width, leaving a significant gap in parameter understanding.

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 function: 'Add an explicit validated trace path between two normalized pad endpoints.' It specifies a verb (add), a unique resource type (trace path), and the specific target endpoints, distinguishing it from sibling tools like route_net or add_via.

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 provides a clear two-step workflow: use dry_run=true to preview, then set dry_run=false and pass expected_sha256 only after inspecting the preview. It implies this is for explicit manual trace placement rather than automatic routing, though it does not name alternative tools explicitly.

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