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

With no annotations, the description carries the full burden and does meaningful work: it declares the tool is paid, documents the failure mode (HTTP 402 with x402Version and accepts), pins cost to refresh.priceUsd ($0.02 USDC on Base), and states a scope boundary ("Vokko never pays the target"). It still omits whether the probe emits traffic to the target or rate/limit behavior, so it is not fully transparent, but the payment/auth profile is unusually well disclosed.

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?

Four short, front-loaded sentences with no filler; cost and payment contract come early. The phrase "named by lookup_host refresh.rest" is cryptic and costs a re-read, which keeps it out of the top band.

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?

There is no output schema and no annotations, so the description is the only behavioral source. It covers payment mechanics well but never says what a successful probe returns or whether the target sees the probe — gaps the agent must guess at for a single-parameter network-touching 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 coverage is 100% and the schema itself exhaustively documents the domain normalization rules (scheme/port/path/www stripping, label constraints, 253-char cap, rejection cases). The description adds nothing about the parameter, 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?

It states a specific action ("paid live re-probe") and names the sibling that supplies the host via lookup_host, which helps separate it from lookup_host itself. However, "re-probe" is never unpacked — what is probed, and at what layer, is left to inference, and the sibling refresh_host_protocol (likely the protocol-level variant) is not contrasted.

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?

Usage is only implied: the phrase "named by lookup_host" sketches a workflow step and the 402 behavior hints at the paid path, but there is no explicit when-to-use vs when-not guidance and no routing against refresh_host_protocol or refresh_hosts_batch.

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