calc_fastener

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

Annotations declare readOnlyHint=true, so no side effects exist. The description adds context about the friction coefficient (K) and torque formula, noting that lubrication changes K dramatically, which is valuable beyond the annotation-only info.

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 sentence that packs many outputs, making it dense. It lacks front-loading or structure (e.g., bullet points) that would improve readability for an agent.

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?

No output schema exists, so the description must convey return format. It lists several computed values (pitch, area, clearance holes, etc.), but does not present them as structured keys or explain the exact output object, leaving gaps.

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 0%, but the description adds meaning to friction_k (default 0.2 dry, lubrication effect) and property_class (proof stress). size_m is implied by the range but not explicitly described, leaving some ambiguity.

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 specific purpose: computing metric coarse-thread fastener numbers for a size range (M1.6–M30). It lists discrete outputs (pitch, tensile stress area, etc.), distinguishing it from sibling calculation tools like calc_fits or calc_beam.

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?

No explicit guidance on when to use this tool versus alternatives is provided. The domain is implied through the list of outputs, but there is no comparison with siblings or conditions for selection.

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