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

With no annotations, the description carries the full burden and does so well: it discloses runtime validation of document and quotas, preservation of server-owned identity/access/creation time, retention of the old revision, whole-snapshot broadcast, and idempotent retry via operationId ('never invent a new id after a lost response'). It omits explicit auth/permission requirements, but token handling is covered in the schema.

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-loads the core operation and its identity/versioning constraints before the dryRun guidance. It is a dense but justified paragraph; a couple of sentences are long, keeping it just short of maximum conciseness.

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?

Given a nested document param, 6 params, and an existing output schema, the definition covers what an agent needs: version-currency, idempotency, validation side effects, idempotent retry, and the dryRun/elicitation fallback. Return values are handled by the output schema, so nothing critical is missing.

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 83% (baseline 3), and the description adds real meaning beyond it: it states baseRevision 'must still be current', clarifies operationId retry semantics, and explains dryRun's no-op validation and elicitation behavior. This meaningfully enriches the parameters rather than restating them.

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+resource ('Replace one stored design from a complete DesignDocumentV1 copy') and frames the scope ('the authoritative save-back and re-import operation'), distinguishing it from get_design, validate, and apply. An agent can identify which sibling performs write-back without reading another schema.

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?

Explicitly routes usage: read from ui_builder_get_design first, and unless the user already chose to save back/re-import onto this home, call with dryRun:true first. It also specifies the elicitation fallback, giving clear when/when-not guidance against alternatives like apply or validate.

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