dns_get

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

Beyond the readOnly/destructive annotations, it discloses substantive behavior: fallback to the parent zone on METHOD_FAILED, the invisible shared-hosting catch-all, and that the `effective` field is fetched by direct UDP query bypassing the resolver cache. One caveat: that explicit external UDP querying sits awkwardly against openWorldHint=false, which slightly tempers confidence.

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?

The purpose is front-loaded, followed by behavioral caveats and then a labeled Args block. It is lengthy for a two-parameter tool, but each sentence (fallback logic, catch-all trap, effective field) adds real interpretive value rather than filler.

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?

For a read-only, two-parameter tool with an output schema and safety annotations already covering the risk profile, the description supplies the missing interpretive layer: how to read absence-of-record, where subdomain data lives, and what `effective` means. An agent can call and interpret it correctly without external clarification.

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%, so the description must carry parameter meaning, and it does: fqdn is documented with valid forms (site.ru or sub.site.ru) and check_effective is explained as 'ask the authoritative NS (default yes)'. This fully compensates for the empty schema descriptions, though the per-parameter notes remain terse.

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 opening sentence names a concrete verb+resource: it returns the FQDN's DNS records plus the authoritative NS response. It is clearly distinguishable from the dns_set_* / dns_patch_record siblings, which are writes. However, it never explicitly contrasts with dns_verify, the other read-style DNS sibling, so it stops short of full sibling differentiation.

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 (inspecting a name's records) and gives scenario guidance for edge cases (METHOD_FAILED fallback, DKIM at parent level, catch-all). It does not state when to prefer this over dns_verify or when to run it before a dns_set_* mutation, so usage is only implied rather than explicitly routed.

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