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

Annotations only declare destructiveHint=true; the description adds substantial operational detail beyond them: automatic promotion of the oldest remaining active domain when a primary is removed, the `removing` status on edge failure, and a background sweep retry loop. This is exactly the kind of side-effect disclosure an agent needs before a destructive call.

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?

Four tight sentences, each carrying a distinct fact: the action, the primary-promotion side effect, the failure/retry path, and the exclusion. The primary action is front-loaded with no preamble.

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 side effects, failure states, and an eligibility constraint well. The only material gap is parameter identification, which is the one thing an agent could get wrong on invocation.

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 0%, so the description must carry the parameter burden. It never explains what `domainId` or `websiteId` identify or how to obtain them, relying entirely on self-explanatory naming; given only 2 flat required string params, this is the minimum viable level.

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 opens with a specific verb and resource: 'Deregisters the hostname from the Cactal edge and deletes the domain record.' It implicitly distinguishes itself from websiteDomains_renamePlatformDomain via the constraint that platform subdomains cannot be removed, but it never names the sibling outright.

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?

The exclusion 'Platform subdomains cannot be removed' tells an agent when this tool does not apply, which is a real usage boundary. It stops short of explicitly routing to an alternative (e.g., renamePlatformDomain), so it falls short of a 5.

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