Set Schematic Component Property

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

Annotations indicate a destructive write operation (destructiveHint=true), and the description enriches this by explaining the property is created if missing, defaults to hidden unless hide=false, persists to the .kicad_sch file, and participates in export_bom and sourcing tools. It adds context beyond the raw annotation, especially the hidden default behavior, which directly affects invocation.

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 well-structured with a clear opening, bullet points for typical properties, and a closing alternative note. It is somewhat verbose for the simplicity of the operation, but every sentence contributes useful context—examples, defaults, downstream effects, and alternatives—so it earns its length while remaining scannable.

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 mutation tool with annotations and an output schema, the description covers the operation's purpose, use cases, alternative when to use edit_schematic_component, default visibility behavior, and impact on exports. It leaves no practical gaps that an agent needs for correct invocation, even for the full 10-parameter schema.

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 input schema has 100% description coverage, so the baseline is 3. The description adds semantic value by listing typical property names (MPN, DigiKey_PN, etc.) and clarifying that 'use empty string to clear' and the hidden default apply within the broader property lifecycle. It doesn't repeat every schema field but reinforces behavior tied to the parameters.

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 opens with 'Add or update a single custom property on a placed schematic symbol,' giving a specific verb and resource. It immediately distinguishes itself from sibling edit_schematic_component by positioning as a 'focused convenience wrapper' for one-property-at-a-time updates, which is clear differentiation.

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?

Explicitly states when to use this tool versus the alternative: 'This is a focused convenience wrapper' for attaching one BOM/sourcing field at a time, and directly instructs 'For batch updates of multiple properties at once, use edit_schematic_component.' This provides clear when-to-use and when-not-to-use guidance.

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