add_domain

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

Annotations only declare readOnlyHint=false and destructiveHint=false. The description adds genuinely useful behavioral context beyond that: the operation requires an authenticated Proof account, must have PROOF_API_KEY set (with a server restart), and can be reached via a start_login session. It does not describe side effects or rate limits, so it is not a 5.

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?

Purpose is front-loaded in a single sentence, followed by a clearly separated ACCESS paragraph. The auth note is somewhat long but earns its place by preventing failed calls; no filler sentences.

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?

Covers purpose, parameters, and the auth prerequisite, which is solid for a mutation tool. With no output schema, the description leaves unclear what a successful call returns or whether ownership is verified immediately, a meaningful gap for an add/verify flow.

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 the schema already documents domain, for_email_sending, and verification_method. The description echoes the two optional params ('email sending intent and verification method') but adds no syntax or format detail beyond the schema, making the baseline 3 appropriate.

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+resource ('Add a new domain') and adds the goal ('to verify ownership'), which lets an agent understand the intent. However, it does not distinguish itself from the many sibling domain tools (verify_domain, start_domain_verification, delete_domain), 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 a prerequisite/route ('needs a Proof account' and use start_login if unauthenticated), which is useful invocation context. It does not, however, explain when to choose add_domain over the other domain-verification siblings, so usage guidance remains implied rather than explicit.

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