New Document

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

Annotations only say readOnly=false, idempotent=false, destructive=false. The description adds real behavioral context beyond that: the call mutates global state by activating the new document, and it explains the deliberate API-vs-UI path because UI-created documents are Part Design documents that reject addNewComponent. It does not say what happens to a previously active document or whether repeated calls stack up new documents, which is the main residual gap.

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 short sentences, front-loaded with the action, then the usage condition, then the design rationale. No sentence is filler; even the API-vs-UI note earns its place by warning about a downstream failure mode.

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 and the description does not say what comes back (document name, handle, or success flag), nor how it interacts with an already-active design. Otherwise it is complete for a stateful entry-point tool, covering purpose, precondition, and the rationale that affects downstream capability.

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% for the single optional "name" parameter, and the description never mentions it, so it adds no naming, defaulting, or collision behavior (e.g. what happens when the name already exists). Baseline 3 applies because the schema fully documents the parameter.

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?

"Create a new design document and make it active" is a precise verb+resource+scope statement. It is clearly distinguishable from every sibling (no other tool creates documents), and it explicitly frames itself as the prerequisite entry point for the rest of the toolset.

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?

It states the exact trigger condition: Fusion sits at the data tab with no active design after a fresh launch, and every other tool requires an active design. That is an explicit when-to-use rule with a stated dependency, 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.