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

Annotations already declare readOnlyHint and openWorldHint, so the safety and external-network profile is covered. The description adds genuinely new behavioral context: the lookup is performed via Cloudflare DNS-over-HTTPS and the response includes TTLs. It does not mention rate limits or failure behavior for non-existent hostnames, so it stops short of a 5.

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?

A single front-loaded sentence with the core action first and the mechanism/return appended. No filler, no redundancy.

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, the description does note what comes back (record data and TTLs), and annotations cover the safety profile, so an agent has enough to invoke it correctly. Minor gaps remain around error/empty-result behavior for a 2-param, single-purpose tool.

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 the param burden. It enumerates the record types that map to the 'type' parameter's enum and implies hostname usage, but adds no semantics such as default behavior (A), accepted hostname format, or what happens on lookup failure. Baseline of 3 for a mostly-schema-restated tool.

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 gives a precise verb ('Resolve'), the exact resource (A/AAAA/CNAME/MX/TXT/NS records for a hostname), the underlying mechanism (Cloudflare DNS-over-HTTPS), and the return shape (record data and TTLs). This cleanly separates it from network-diagnostics siblings like check_ssl or trace_redirects without needing to name them.

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 makes the usage context implicit (DNS record resolution, a diagnostic task) but never states when to reach for this tool versus check_url_status or trace_redirects, nor any prerequisites. Adequate but no explicit 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.