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

Annotations already cover the safety profile (readOnly/idempotent/non-destructive), and the description adds substantial context beyond them: the exact checks run, their thresholds and defaults, the pass/fail/warn outcome space, diagnostics, and the precedence rule that dfmSpec settings act as defaults while call options win.

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?

Front-loaded with the use case and return shape, then organized by process (FDM block, CNC block, return shape, precedence). It is dense and list-heavy, but every clause carries operational information and nothing is redundant with the title.

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 an 11-parameter, zero-required, multi-check tool this covers everything an agent needs: input alternatives, defaults, per-check trigger conditions, result shape and the sibling to use for a different class of checks. The output schema exists, but the description's restatement of verdict/checks semantics is additive rather than filler.

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%, so the baseline is 3; the description still earns credit by explaining derived semantics the schema cannot, e.g. that min-wall triggers under 2 × nozzle_mm and min-hole under 5 × nozzle, and that listing several approach_axes corresponds to several CNC setups. Some defaults (printer, max_bridge_mm, tool_diameter_mm) are simply restated from 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?

States a specific verb and resource ('returns a pass/fail checklist' for a 'manufacturability (DFM) report') and bounds the scope to pre-printing/machining review. It also distinguishes itself from the nearest sibling by explicitly routing script-declared gates to verify({ check: 'dfm' }).

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?

Opens with an explicit when-to-use trigger ('before printing or machining a part') and names the alternative with its selecting condition ('For the script-declared gates ... use verify'). It also clarifies that no dfmSpec(...) declaration is needed, removing the most likely invocation mistake.

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