Infrastructure Pivot

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

Annotations already declare readOnly/idempotent/non-destructive, and the description goes well beyond them: API-key requirement with exact header and env-var forms, the 20-row-per-call limit, rate limiting, and the key operational caveat that shared infrastructure degrades to a count. Coverage limitation (only DechoNet's own observations) is also 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?

Front-loaded with the core action and purpose, then layered with the degradation rule, auth requirements and limits. Dense but every clause carries operational information; the auth parenthetical is slightly compressed but not wasteful.

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?

Output schema exists so return values need no explanation, and the description supplies everything else an agent needs: prerequisites, sequencing relative to sibling tools, auth, quota and coverage limits. Nothing material to correct invocation 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% with an enum for kind and an example for value, so the baseline is 3. The description adds real meaning by naming which infrastructure categories the enum members correspond to (nameserver, IP address, MX host, certificate issuer, registrar), tying abstract enum strings to concepts, though it does not explain individual enum members one by one.

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?

States a specific verb (find) and resource (other domains sharing an infrastructure value) plus the scope of the pivot values (nameserver, IP, MX, certificate issuer, registrar). Gives a concrete motivating example (other phishing domains on the same rare nameserver), so an agent can distinguish it from dns_lookup or reverse_dns without opening either 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?

Explicit about when to use it — 'after domain_history or dns_lookup gives you a distinctive value' — and when it is useless, since shared infrastructure (CDNs, public CAs, large registrars) returns only a count. Both the trigger condition and the negative case are named.

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