Add Layer

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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the agent knows this is a mutating operation. The description adds no further behavioral context, such as effects on existing layers, ordering constraints, or reversibility, but it doesn't contradict the annotations. Since annotations carry the safety profile, the minimal description is acceptable though not enriched.

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 a single sentence that leads with the action verb 'Add' and directly states the object and destination. Every word earns its place, with no filler or repetition. It is optimally sized for a tool with this level of complexity.

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 there are 4 parameters with enums and an output schema, the description is adequate but incomplete. It does not explain the relationship between layer type (copper/technical/user/signal) and position (top/bottom/inner), nor when the optional 'number' parameter is needed. Since the output schema exists, return values are not an issue, but the tool could benefit from more guidance on parameter selection.

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% with per-parameter descriptions in the input schema, so the baseline is 3. The description adds minimal semantic value by mentioning 'copper or technical' layer types, but it partially screens out 'user' and 'signal' enums. No additional parameter guidance is provided beyond what the schema already states.

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 action ('Add a new copper or technical layer') and the target ('PCB stackup'), distinguishing it from siblings like set_active_layer or get_layer_list. However, it omits the 'user' and 'signal' layer types that are allowed in the schema, making the stated scope slightly narrower than actual capability.

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 phrase 'to the PCB stackup' implies the tool is used for adding layers to the board, but it does not explicitly state when to use this tool versus alternatives, such as set_active_layer or get_layer_list. There is no mention of when not to use it or any preconditions like board state requirements.

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