静态 UI 默认入口：规划可编辑场景节点，检查版本、引用和名称冲突，返回 planHash

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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuine value beyond that by disclosing the pre-checks performed (version, reference, name-conflict validation) and the returned `planHash`, which is important given there is no output schema. It does not explain what the planHash is for or whether planning mutates any server-side state.

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?

It is a single front-loaded sentence with no redundant wording, but for a tool with one of the largest nested schemas in the sibling set this is under-specification rather than true concision. The core intent lands first, which is good, but the sentence is effectively a restatement of the title.

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?

With a 6-parameter schema, recursive node trees, 0% parameter documentation and no output schema, the agent needs to know what the plan does not do (it does not apply), how `expectedRevision` interacts with conflict checking, and how to use the returned `planHash`. None of that is present; only the high-level intent and the return token are covered.

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% across 6 parameters, including a deeply nested `document.root` tree with node keys, transforms and 13 component variants, plus `expectedRevision`, `operationId` and `instanceId`. The description's mention of '版本' hints at version checking but never maps to `expectedRevision` or `document.version`, and says nothing about `parentId`, `projectId`, concurrency tokens, or idempotency keys.

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?

Tautological: description restates name/title.

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?

'默认入口' signals this is the first step in the static-UI flow, which implies a plan-then-apply sequence against `cocos_ui_build`. But there is no explicit when-to-use/when-not, no mention that the result is a non-applied plan requiring a follow-up call, and no guidance on prerequisites such as an active project connection.

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