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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds real value beyond that by disclosing data provenance (whois/RDAP, latest port scan, DNS blocklist) and the default-returns-all behavior, though it omits latency or freshness caveats for the scan/blocklist data.

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 behavioral content is front-loaded in one dense sentence before the documentation links, so an agent gets the essentials immediately. The three appended doc URLs are somewhat bulky but plausibly useful pointers rather than pure padding.

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 an output schema present, the description needn't explain return shapes, and it does cover all three data sections plus the default selection behavior. It is essentially complete for invocation; only the absence of any when-to-use guidance and freshness notes keeps it from the top.

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 parameters are already documented in the schema, and the description largely restates the sections enum and the default. Baseline 3 is appropriate since it adds little syntax or format detail beyond what the schema provides.

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 (get) and resource (domain intel) and enumerates the three concrete sections returned — registration/expiry via whois/RDAP, open ports from the latest scan, and DNS blocklist status. This distinguishes it from nearby siblings such as get_dns_records or get_certificate_health without requiring the schema.

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 frames the tool as showing 'what the outside world can see about a monitored domain' and notes that all three sections return by default, which implies when the full payload is appropriate. However, it never states when to prefer this over a narrower sibling or when to limit sections, so usage is only implied.

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