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

Annotations already declare destructiveHint=true and idempotentHint=false, but the description adds real value: authentication requirement, the explicit 'Does not charge' cost disclosure, and the fact that the domain lands on a new site showing a coming-soon page. It still does not describe failure modes or whether the domain is removed from the original site immediately.

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, prerequisite front-loaded, no filler. Every clause carries information an agent needs: auth, effect, dry-run control, and cost.

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 3-required-parameter mutation tool with no output schema, the description covers auth, cost, side effects, and the dry-run switch, so an agent can call it correctly. Minor gaps remain around what happens if the site has only one domain or whether the move is reversible.

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 all three parameters are already documented, establishing a baseline of 3. The description reinforces the 'site that has several' constraint on the domain parameter and the confirm semantics, but adds no format or edge-case detail beyond 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 and resource ('Moves one domain off a site that has several, onto a new site') with a clear precondition (site must have multiple domains). It is distinguishable from siblings like connect_domain, point_domain, and make_primary_domain by the 'moves off ... onto a new site' framing, though it never names an alternative explicitly.

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?

Gives a prerequisite ('needs account token') and the semantics of confirm=true/false, which implies the usage pattern (dry-run first, then apply). It does not say when to prefer this over siblings such as connect_domain or transfer_domain_out, nor any exclusions.

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