scl_diff

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

With no annotations, the description carries the full burden of disclosing behavior. It explains that the tool compares the parsed model rather than raw text, which is a key behavioral trait. It also lists the specific output categories, but it does not mention side effects (e.g., read-only) or error handling. The transparency is good but not exhaustive.

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 concise and front-loaded: the first sentence states the primary purpose. The second paragraph adds valuable context about why this tool is necessary, with no wasted words. Every sentence contributes to understanding the tool's purpose and 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 complexity (diffing parsed SCL models) and the presence of an output schema, the description provides a reasonable overview. It lists the main categories of differences and explains the rationale. However, it omits details like file path requirements, error scenarios, or how output is structured beyond the schema, and it lacks explicit read-only confirmation.

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 zero description coverage, so the description must compensate. It identifies the two parameters as 'two SCL files' with roles 'as-built vs. design review', but it does not explicitly map baseline_path to as-built and candidate_path to design review. It provides some semantic context but leaves the mapping implicit; this partially fills the schema gap but could be clearer.

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 with a specific verb and resource: 'structurally compare two SCL files'. It further specifies the comparison scope (as-built vs. design review) and enumerates the types of changes detected (added/removed/changed per IED, logical device, dataset, etc.), which distinguishes it from sibling tools like scl_summary or scl_validate.

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 strong context for when to use the tool by explaining why text diff is unusable for SCL files (PCM600 reorders elements and rewrites attributes). It implicitly advises using this tool for comparing as-built vs. design review. However, it does not explicitly name alternative sibling tools or state 'use this instead of X', so it lacks explicit exclusions.

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