Nodes, elements and bridge layouts / 节点单元与桥梁布置

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

Adds substantial behavior beyond the annotations (destructive=true, idempotent=false): 'Writes require an editable model and can invalidate solved data,' 'Batch and workflow calls are not transactions: earlier writes can remain after failure,' and 'a confirmation is not always a readback.' These tell the agent about partial-failure risk and required readback, which the annotations do not. It stops short of a 5 only because per-operation specifics (already covered in nested schemas) carry much of the remaining detail.

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 verb/resource statement, then routing, then constraints, then write semantics - a logical order with no filler sentences. It is dense and clause-heavy in the routing paragraph, and the length is driven by legitimate complexity (22 branches), so it earns its size without being padded.

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?

Covers everything an agent needs before calling a destructive, non-idempotent geometry editor: prerequisites (referenced entities must exist), enumeration-selection guidance, ID-assignment pitfalls, confirmation-vs-readback caveats, and the reminder that analysis is a separate step. Return values are handled by the output schema and the per-branch 'Returns:' blocks, so the description is complete for this complexity.

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, but the description adds cross-cutting meaning the schema does not: 'Referenced materials, sections and nodes must exist; plate thickness is distinct from a frame section,' 'Explicit IDs can be reassigned or reused by merging,' and the renumber pairing rule ('both paired lists, or neither for a global renumber'). The routing sentence ('Supply request.operation and that branch's fields') clarifies the discriminator contract.

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 specific verbs and resources ('Create, edit, renumber, merge or remove model nodes and elements') plus the domain ('standard straight-girder workflows'), and it explicitly carves out sibling territory (edit_properties for materials/sections, edit_boundaries for supports, view_model for display). The only reason it isn't a 5 is that the top-level statement spans 22 discriminated operations, so the single 'purpose' is broad and only fully resolved by the nested branch schemas.

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?

Gives explicit routing both internally and externally: 'Targeted update_element_* operations change one property; update_element edits a record. update_node sets absolute coordinates, move_nodes adds offsets, and renumbering changes IDs,' and 'Use edit_properties ... edit_boundaries ... view_model to change only the display.' It also closes the loop with 'Solving is a separate analyze_model operation,' leaving nothing to inference.

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