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

Goes well beyond the annotations by disclosing the copied scope, that the original is untouched, that the copy has no address or custom domain, that it counts against the draft-site limit, and that the new site's id is returned. These are exactly the side effects an agent would otherwise have to guess at.

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 tight sentences, front-loaded with the core action and scope, followed by constraints and return value. No waste or redundancy.

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, but the description supplies the return value (new site's id) and the key side-effect limits. For a three-parameter mutation with full schema coverage, nothing an agent needs to invoke it correctly 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 description coverage is 100%, so the schema already documents site_id, name, and user_goal. The description adds no parameter-level detail beyond noting the return id; the schema is doing the heavy lifting, so baseline 3 applies.

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?

Uses a specific verb (copy) plus explicitly enumerates what is copied — code, design, content, and every design — and the output artifact (a new draft site). This clearly distinguishes it from create_site, create_site_from_design, and rename_site among the siblings.

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?

States the conditions of the result (draft, unpublished, no address, counts toward the plan's draft-site limit) which tells the agent when this is the appropriate action. It does not, however, explicitly contrast with create_site or create_site_from_design, so the alternative selection is left implicit.

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