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

With no annotations, the description carries the full burden and delivers: a 20-indicator cap, the critical interpretation caveat that found:false means 'nothing recorded', not 'safe', the free-batch rule when nothing is found, and the payment gate mechanics (x402 via _meta, PAYMENT-SIGNATURE header, or Gumroad X-API-KEY). This is exactly the non-obvious behavioral context an agent needs before calling.

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-loads purpose and uses explicit SIBLING DIFFERENTIATION and BEHAVIOR labels, which aids scanning. It is dense and somewhat long, but nearly every sentence (payment gate, found:false semantics) carries operational weight.

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?

No output schema exists, yet the description covers the return semantics (aggregated provenance, found:false behavior), the batch-size limit, pricing, and auth. Combined with a fully described schema, an agent has everything needed to call it correctly.

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% for the single 'values' parameter, so the schema already documents its type and content. The description restates the accepted indicator types and the max-20 limit, which is largely duplicative; baseline 3 is appropriate.

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 and resource ('looks up multiple indicators (IPs, domains, URLs, hashes) in a single call') and immediately frames the use case as a batched pre-action safety check. It names the sibling it is not (get_ioc_context) and the bulk alternative (get_threat_indicators), so an agent can distinguish it without opening another 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 when-to-use ('checking several indicators at once, e.g. all URLs an agent is about to visit') plus two explicit when-NOT cases routing to get_ioc_context for singles and get_threat_indicators for bulk feed sync. Nothing is left to inference.

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