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

Goes well beyond the annotations: it discloses the auth requirement (regular org membership, not billing-only), the create-or-return-existing semantics, the archived-domain restore path, and the fact that no DNS records are touched. The annotations only declare readOnly=false, idempotent=true, destructive=false; the description supplies the operational detail that makes those hints actionable.

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 short sentences, each carrying distinct information (action, permission requirement, idempotent/restore behavior, non-effect on DNS). The clause "This adds the domain to Suped" is mildly redundant with the opening sentence, keeping it from a 5.

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?

With no output schema and only two required params, the description covers the essentials: what happens on success, what happens if the domain exists, and the permission model. It does not describe the returned domain object's shape or any normalization behavior, a minor remaining gap.

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 50%: 'domain' is documented in the schema, while 'organizationId' only carries a 24-hex pattern with no explanation. The description references "the specified Suped organization" but adds no guidance on how to source or format that ID, so it neither compensates for nor worsens the gap.

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 ("Adds a domain to the specified Suped organization") and explicitly bounds the effect ("does not change the domain's DNS records"), which cleanly separates it from siblings like get_domains and get_dmarc_records.

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?

It states a real precondition — regular organization access, with billing-only membership insufficient — which tells the agent when the call will fail. It stops short of explicitly routing between siblings (e.g., when to use this vs. get_domains), so it is clear context but not full when/when-not guidance.

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