add_domain

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

No annotations are provided, so the description carries the full burden. It usefully discloses that the call returns DNS records to configure, but says nothing about idempotency, behavior when the domain already exists, error conditions, or the relationship to verify_domain.

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?

Two short sentences, action first and the return-value note second. Every clause earns its place with no filler.

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, so the description's mention of returned DNS records is a valuable hint, but it stops short of describing what those records are or the follow-up verification step. For an unannotated mutation tool in a domain-management family, more behavioral detail is warranted.

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 100% with a single documented 'domain' parameter including an example format, so the schema does the heavy lifting. The description adds no semantics about domain constraints (subdomains, verification requirements) beyond what the schema 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?

Specific verb ('Register') plus resource ('sender domain'), which cleanly separates it from list_domains, get_domain, verify_domain and delete_domain by implying creation of a new domain. It does not explicitly name those siblings, but the verb carries enough signal for an agent to choose correctly.

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?

Usage is only implied: an agent can infer this is the setup step before sending from a domain, and that verify_domain likely follows. There is no explicit when-to-use, when-not-to-use (e.g. domain already registered), or prerequisite statement.

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