diff_mto_scsa

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

With no annotations provided, the description carries the full behavioral burden and meets it: it discloses read-only side effects, the exact scenarios returned (qty_mismatch, removed, new), and that matching items only appear as a count in summary.matched, not as a list. This goes well beyond a generic 'compare files' statement.

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 efficiently front-loaded with the core action and safety characteristic, then organized into scenario and argument lists. Every sentence adds information; there is no filler or repetition of schema titles.

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 three-parameter comparison tool with no output schema, the description covers inputs, optional filtering, output scenarios, and the special handling of matched items. An agent has enough context to invoke it and interpret the result categories 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 description coverage is 0%, so the description must explain the parameters itself. It does so thoroughly: mto_path and scsa_path specify file types, and category is listed with the full set of allowed values plus the default behavior when omitted.

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 a specific verb and resource ('Compare an MTO file against a Plant 3D SCSA export') and names three concrete diff scenarios. This makes the tool's purpose immediately clear and distinguishes it from the sibling apply_mto_update, which implies writing changes.

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 states this tool is 'Read-only - never writes anything', signaling not to use it for modifications and implying apply_mto_update is the writing counterpart. It also explains the optional category filter and its omission behavior. However, it never names apply_mto_update explicitly as the alternative for applying changes.

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