DFA Check

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

With annotations already marking the tool read-only, the description adds substantial behavioral context: the exact efficiency formula, the handling penalty from insertion_axes/symmetry, monotonic decrease with part/fastener count, and the fixed fidelity/band_pct output values. It does not contradict the annotations, though it omits edge cases like zero counts or invalid fractions.

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?

Two dense sentences pack the purpose, formula, caveat, and return structure without filler. The primary action is front-loaded, and every clause earns its place given the sparse schema.

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?

Despite no output schema or parameter descriptions, the description provides the formula, usage caveat, and the full set of returned fields. It is complete enough to call and interpret results for comparative DFA screening, but it lacks validation guidance and interpretation of handling_difficulty/symmetry_score levels.

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 carries the burden. It explains part_count and fastener_count through the denominator, unique_part_count through theoretical_min, and insertion_axes/symmetry through the handling penalty. However, symmetric_fraction is only implied as 'symmetry' and no bounds or validation semantics are given, so it stops short of full compensation.

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: 'Grade an assembly (Boothroyd-Dewhurst-lite).' It goes beyond a one-line summary by stating the scoring formula and the ordinal nature of the grade, which clearly separates it from sibling tools like dfm_check or cost_estimate.

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?

It gives a clear usage directive: use the grade for comparing variants and explicitly warns not to gate on the absolute value ('rank with it, don't gate on the absolute value'). However, it does not name alternatives or explicitly state when not to use this tool versus another.

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