mailX tools

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

Annotations cover read-only, non-destructive, idempotent, and open-world hints. The description adds value by specifying the scope ('all DNS records') and return types, which are not in annotations. No contradiction with annotations.

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 sentences, front-loaded with the core purpose, no wasted words. Every sentence adds value: the first defines the action and scope, the second lists return types.

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?

Given the tool's low complexity, rich annotations, and 100% schema coverage, the description is mostly complete. It lacks output schema, but the return types are listed, compensating adequately. Could improve by mentioning error cases or limitations.

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%, with the parameter 'domain_name' fully documented. The description does not add meaning beyond the schema, such as format details or examples, so baseline 3 is 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?

The description clearly states the verb ('Look up') and resource ('DNS records for a domain'), specifying it returns multiple record types (A, AAAA, CNAME, MX, NS, TXT, SOA). It distinguishes from siblings like mx_lookup or txt_lookup by emphasizing 'all DNS records in one query'.

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 implies usage for comprehensive DNS queries, but does not explicitly state when to use alternatives like mx_lookup for specific record types or other sibling tools. It provides clear context for bulk lookups without naming exclusions.

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