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

Annotations already cover the key behavioral traits: readOnlyHint=false, destructiveHint=false, idempotentHint=true. The description adds context about record types and value formats but does not disclose additional behavioral nuances such as duplicate handling, propagation delay, or conflict behavior. With annotations carrying the safety profile, this is adequate but not exceptional.

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?

Three sentences, front-loaded with the primary purpose and scope, followed by compact format guidance for MX and SRV. No filler or redundant detail; every sentence contributes to correct usage.

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?

The combination of a 100%-covered schema, an output schema, and annotations covers most operational needs. The description adds situational examples and special value formats. Minor gaps like possible duplicate/conflict behavior or propagation timing are not essential for invoking the tool correctly and are not expected given the richness of the structured data.

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 every parameter in detail. The description adds some reinforcement, especially for MX and SRV value formats, but it mostly repeats what the input schema already states. There is no significant new semantic information beyond the schema.

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 specific verb and resource ('Adds a DNS record to a custom domain') and gives concrete use cases like email provider setup and verification records. It also lists the supported record types, clearly distinguishing this from sibling tools like delete_dns_record and list_dns_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?

The description provides clear context for when to use the tool, with examples such as setting up email providers or verification records. It does not explicitly name alternatives or state when not to use it, but the examples and record-type list make the intended usage clear.

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