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

Annotations already mark it read-only, idempotent, open-world, and non-destructive, so the description only needs to add behavioral context. It adds that data is polled every 3 minutes over DoT and that each card carries the time it was read, which helps an agent understand freshness.

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 short sentences, no filler; the purpose is front-loaded and the useful caveat (optional resolver gives one card) is in the second sentence. Every clause adds information.

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 simple optional-parameter read tool with no output schema, the description tells an agent what data to expect (status, latency, DNSSEC, read time), how fresh it is, and how to scope it. Nothing essential for a correct call is missing.

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%, so the parameter is already well-documented with accepted resolver ids, aliases, addresses, and the omit-for-whole-board behavior. The description adds only the 'one card' consequence of passing a resolver, which is minor added meaning.

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 opens with 'live board' and the question 'is public DNS OK right now?', naming a specific resource (public resolvers watched by isitdns) and the data returned (status, latency, DNSSEC, read time). The phrase 'live' differentiates it from the sibling resolver_history without needing any schema inspection.

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 clearly frames when the tool is appropriate: for current resolver health, with freshness signaled by 'right now' and 'every 3 minutes.' It does not explicitly name a sibling alternative like resolver_history for historical queries, but the live-vs-history context is clear enough.

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