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

Annotations already declare destructiveHint=true, non-idempotent and open-world, and the description is consistent with that ("replace"). It adds real value beyond the annotations by disclosing the cost profile ("Free — does not spend Creative Credits"), but it does not say whether the prior draft text is recoverable (e.g. via restore_version) or what the call returns.

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 with the action, the id source and the cost caveat front-loaded; nothing is redundant and no sentence is wasted.

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?

For a destructive, non-idempotent mutation with no output schema, the description covers the id source and cost but omits what happens to the existing draft content, whether a new draft is produced, and whether the call is synchronous/long-running.

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 phrase "what to change, in their words" adds genuine meaning about the message parameter — freeform natural language rather than a structured edit spec. brand_id and user_goal are left entirely to the schema.

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 (rewrite/replace) and resource (one content draft), plus names the sibling list_content_drafts as the id source, so an agent can distinguish it from create_page_draft or list_content_drafts without opening a 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?

"Rewrite and replace one draft from list_content_drafts" tells the agent the precondition (an existing draft id) and the workflow entry point, and the credit note gives a reason to prefer this over a generative alternative. It stops short of naming an explicit alternative or when-not-to-use case.

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