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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds the access-scoping rule (only domains owned by the authenticated customer) and the fact that the response carries zone record IDs, but says nothing about pagination, empty results, or result size for large zones.

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, front-loaded with the action and scope, with no filler. The second sentence carries actionable follow-up information rather than padding.

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?

An output schema exists, so return structure need not be described; the description covers ownership scope and the key returned identifier. The remaining gap is the ambiguous 'domain' argument format, which an agent needs to call correctly.

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 0% and the single required parameter 'domain' is unexplained — the description does not clarify whether it expects a registrable name, a subdomain/FQDN, or an internal zone identifier, which directly affects whether the call succeeds. It only restates that the domain must be customer-owned.

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 ("List the managed DNS records") and scopes it to domains owned by the authenticated customer, which separates it from broader tools like list_domains. It does not name the update/delete siblings explicitly, but the read-only listing purpose is unambiguous.

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?

Gives a clear workflow cue: use this to obtain the record ID needed before updating or deleting a record, which implies the correct call ordering against update_dns_record/delete_dns_record. No explicit 'when not to use' or alternatives are listed, so it stops short of a 5.

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