plasticity_check_fastener_stack

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

Annotations already declare readOnlyHint/openWorldHint=false/destructiveHint=false, so safety is covered. The description adds genuine behavioral context beyond them: it is deterministic, it treats every layer/envelope/engagement/tip-clearance/datum value as a caller-supplied explicit input (no implicit defaults assumed), and it enumerates what the result explicitly does NOT assert. That is useful disclosure, though it says nothing about failure modes or result shape.

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?

Three sentences, front-loaded with the core action and followed by the input-policy and boundary clauses. Every sentence carries information, though the second sentence is dense and slightly awkwardly phrased ('remain explicit inputs'), keeping it just short of a clean 5.

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 tool with a 5-parameter schema including a two-branch oneOf receiver, 4 required params, and no output schema, the description is thin: it correctly avoids explaining return values but does not clarify the designation input format or how nut vs threaded receivers change required inputs. The stated scope boundary is the main thing keeping it at minimum-viable.

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 compensate, and it partially does: 'clamped stack' maps to gripItems, 'nut/washer envelope, engagement, tip clearance' maps to the nut/threaded receiver variant fields, and 'under-head versus overall length datum' maps to lengthMeasurement. It still leaves the designation string format and the broader receiver oneOf branches undocumented, so coverage remains incomplete.

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 ('Check whether the nominal length ... fits an explicit clamped stack') with a precise scope (ISO metric screw/bolt designation, nut or threaded receiver). The closing negative clause ('does not claim strength, preload, access, fit, or thread-stripping capacity') cleanly separates it from the many strength-verification siblings without needing to name them.

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?

Usage is implied rather than stated: the phrase 'explicit inputs' and the deterministic scope note tell the agent this is a pure length/fit check, and the negative clause hints at when-not (anything strength-related). However, it never explicitly names alternatives like measure_fastener_grip_stack or resolve_fastener_designation, nor the condition selecting them, so guidance stays at implied level.

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