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

The description explicitly states 'Persists the result', i.e. a write/side effect, while the annotations declare readOnlyHint=true (does not modify its environment). That is a direct contradiction. The A-record fallback detail is useful, but the stated persistence behavior conflicts with the declared read-only contract.

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 compact sentences front-load the behavior and the fallback case, followed by a compact metadata block (group, endpoint, cost) with no wasted prose. Slightly dense but well ordered.

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 values need not be explained, and annotations cover the safety profile. However the description omits prerequisites (domain must first be configured via whitelabel_config) and does not clarify what persisting the result affects, which matters for a verification tool that claims to write state.

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 both generic response-shaping params (fields, precision) are already fully documented in the schema. The description adds no parameter-level meaning of its own, so the baseline 3 applies.

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 ('Check whether the configured custom_domain points to api.astroway.info via CNAME') and even names the exact expected target, so an agent can tell immediately what the call does. It is cleanly separable from the other whitelabel siblings (config/logo/preview), none of which overlap with DNS verification.

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?

It implies the right moment ('the configured custom_domain', i.e. after setup) and explains the A-record fallback outcome, but never explicitly says when to use this versus astroway_whitelabel_config or after which setup step, and gives no prerequisites or when-not guidance.

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