cloud_app_domain_add

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

With no annotations, the description carries the full behavioral burden. It discloses that the API returns CNAME instructions and that HTTPS verification should wait for DNS, which is meaningful. It does not mention mutation side effects, idempotency, failure conditions, or costs beyond what sandbox implies.

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 first sentence about deploy timing (~2–3 minutes, 10–20 seconds) is irrelevant for adding a domain and adds noise. The bilingual repetition lengthens the text, and the core instruction is buried in the middle rather than front-loaded.

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?

There is no output schema or annotations, so the description must define both behavior and return. It does mention CNAME instructions, which is helpful, but it leaves app_id semantics, exact response shape, approval failure handling, and the overall add-domain workflow incomplete.

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 only 33% (only sandbox is described), so the description must compensate. It implies host is the custom domain and adds the important "approved domain" constraint, but it never explains app_id or how host relates to the CNAME flow. Two required parameters remain effectively undocumented.

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?

"Attach custom domain" and "Thêm domain đã được duyệt" clearly state the verb and resource. The operation is distinct from app create, list, host list, deploy, and logs siblings. It does not differentiate from the nearly identical vibecloud_app_domain_add sibling, so it stops short of a 5.

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 description gives useful context: the domain must already be approved and you must wait for DNS before checking HTTPS. However, it never explicitly states when to use this tool versus alternatives, nor does it mention prerequisites like needing an existing deployed app or where to get app_id.

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