vibecloud_app_domain_add

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

With no annotations provided, the description carries the full burden, and it delivers: it discloses that the API returns CNAME instructions, that DNS propagation must precede HTTPS verification, and gives live-app timing expectations (~2–3 min for first host, 10–20s for deploys). It does not cover auth requirements, reversibility, or duplicate-domain behavior, but the core workflow is transparent.

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 three bilingual sentence-pairs are compact but redundant, repeating each idea in Vietnamese and English, and the English halves are telegraphic and incomplete (e.g., 'Git apps are live.' omits the timing numbers that appear only in Vietnamese). The core purpose line sits at the end rather than being front-loaded, though the alias identity is appropriately placed first.

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?

Given no annotations and no output schema, the description covers the operational essentials: what to attach, the prerequisite of an approved domain, the CNAME instructions returned by the API, and the DNS-before-HTTPS sequencing. Gaps such as response structure, error handling, and duplicate-domain behavior are minor given how well the end-to-end workflow is conveyed.

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 only 33% (host and app_id are undocumented in the schema), so the description needed to compensate. It partially does: 'custom domain' maps to host and implies it must be pre-approved ('đã được duyệt'), and 'App từ git' ties app_id to a git deployment. However, it never names the parameters explicitly and adds nothing about sandbox beyond what the schema already states.

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 states a clear verb+resource: 'Attach custom domain' / 'Thêm domain đã được duyệt' (add approved domain), and explicitly identifies itself as a compatibility alias of cloud_app_domain_add, which separates it from that sibling. It loses a point because the bilingual mix muddies the message: the English tagline is a bare phrase while the substantive detail lives only in Vietnamese.

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 alias note ('Compatibility alias') gives the agent the key routing signal that this is equivalent to cloud_app_domain_add, but it never states which variant to prefer or when an alternative would be more appropriate. The DNS sequencing guidance ('wait for DNS before checking HTTPS') provides operational context, but there are no explicit when-to-use or when-not-to-use rules.

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