Update a pad

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

Annotations already mark destructiveHint=true and readOnlyHint=false; the description complements them by disclosing the conditional cascade to per-layer tables on stacked pads and the response count behavior. It does not discuss overwrite/reversibility, but the destructive annotation lowers that burden.

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 purposeful sentences: core purpose, operational lookup, and the one non-obvious side effect. No filler or repetition of schema boilerplate; the nuance is placed after the primary use case.

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 no output schema, the description supplies some return information ('response reports how many followed') and the schema covers all parameters. It could still say what a normal success response looks like, but for a moderate-complexity mutation this is a minor gap.

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 coverage is 100% and each parameter has a good description, so the baseline is 3. The description adds real value for width/height/shape by explaining exactly how updates propagate on stacked pads ('layers that shared the old primary value follow it...'), going beyond the schema.

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?

States a specific verb and resource: 'Update specific properties of a pad in a PcbLib footprint'. It also clarifies scope with 'without replacing the entire component' and 'Find pad by designator', distinguishing it from whole-component rewrite tools like write_pcblib or update_component.

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 communicates clear intended usage: targeted partial pad changes via designator, not whole-component replacement. It does not explicitly name alternative tools or state when-not-to-use conditions, so it misses the full 5, but the context is clear enough for routing.

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