Architecture: Structural Grid

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

Annotations carry only destructiveHint=false, so the description does real work: it states that all refusals occur before any write (validation-first, non-destructive on failure), which layer supplies the center linetype, where bubbles are placed, and that sizes are server-declared paper mm rather than a standards value. It stops short of stating idempotency or what happens to pre-existing grid entities, but the failure semantics are unusually explicit.

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 tight paragraphs, front-loaded with what gets drawn, then convention, then refusal conditions. The refusal enumeration is long but each item is a distinct error case with no filler, so it earns its space.

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?

An output schema exists so return values need no explanation, and the description covers layer sourcing, sizing semantics, labeling convention, and failure modes. Minor gaps remain around layer names/prerequisites and whether callers must pre-create those layers, but overall it is complete for a 2-required-param drafting tool.

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 meaningfully extends it: it explains that labels override the default numbering per position in given order, clarifies the mm-vs-paper-mm relationship for scale, and enumerates the specific invalid values that trigger refusal for scale/extension and label lists.

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?

Specific verb+resource: creates axis lines with end bubbles and labels on the arch grid/symbol layers. The detail about center linetype origin, bubble size, and numbering scheme makes it unmistakably distinct from siblings like centre_marks, arch_dimension_chains, or dimension_auto.

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 by the content (this is the tool for setting out a structural grid), but there is no explicit when-to-use or when-not-to-use guidance, and no alternative sibling is named for cases where the agent might want dimensions or centre marks instead.

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