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

Annotations only say readOnlyHint=false, openWorldHint=true, destructiveHint=false; the description adds genuinely new behavior: drafts are private, browser-owned, expire after 15 minutes or a browser reload, and a slot argument changes preview scoping. It also discloses the security constraint that previewURL must never be posted in chat — none of which the annotations convey.

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?

The description is dense but front-loaded: creation and its scope come first, then lifetime, then the parameter nuance, then the prescribed workflow, then the hard constraint. Every clause carries a distinct instruction and nothing is restated from the title or schema.

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?

Behaviorally it is thorough for a complex tool with no output schema, covering lifetime, scoping and the downstream screenshot/publish chain. But with 11 parameters at 9% schema coverage and no output schema, an agent still cannot learn what controlToken, expectedRevision, operationID or the data/state payloads mean, which is a real gap for a mutation-intent 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 description coverage is only 9% across 11 parameters (7 required), so the description carries most of the burden — yet it explains only the optional slot parameter ("drafts a nested sub-component only, preview is slot-scoped"). Required fields like operationID, expectedRevision, controlToken, action, format, componentID, data and state get no semantic explanation anywhere.

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?

The description uses a specific verb+resource pair ("Creates a private browser-owned component draft and preview URL") and immediately scopes it ("without changing the live workspace"), which cleanly separates it from create_component, update_component, publish_draft and update_draft in the sibling list. An agent can tell what this tool produces (a draft ID plus a scoped preview URL) without opening the 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?

It routes the agent through a concrete sequence (prepare_draft -> screenshot_draft with draftID and expectedVersion -> grade density/dead space/icons/clipping/broken panels -> publish_draft) and states the previewURL handling rule. It lacks an explicit "when not to use this" clause versus create_component/update_component, relying on the phrase "without changing the live workspace" to imply the boundary.

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