Plumb · diff

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

The description discloses output format (structured deltas with summary, not JSON diff), narration using role labels, and the fact that it only compares two documents. Annotations (readOnly, idempotent) are consistent and description adds value beyond them.

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 well-structured paragraph that covers purpose, prerequisites, output format, and constraints without wasted words. Every sentence adds value.

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 the tool's simplicity (2 params, no output schema), the description fully covers what the tool does, how to use it, and what to expect in return. It is complete for an AI agent to use correctly.

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%, but the description adds meaning by explaining that parameters must be full PdsDocument objects from specific tools and that nodes+root fields are required. This provides context 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?

The description clearly states it performs a semantic diff between two PDS snapshots of the same screen, specifying the verb (diff) and resource (snapshots). It distinguishes from siblings by noting it does no live Figma fetching.

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 explicit usage instructions: call plumb_node (or outline/query) before and after a change, then pass the responses here. It clarifies what it does not do (no live fetching), but does not name explicit alternatives.

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