Defang IOCs

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

Annotations already cover readOnly, idempotent, non-destructive and closed-world, and the description's 'Idempotent' merely restates one of them. However, it adds genuinely new behavioral information beyond the annotations: the specific substitution forms used and the fact that extracted indicators are also returned, which matters since there is no output schema.

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?

A single sentence that front-loads the verb and resource list, then the rationale, then the side output. Nothing is redundant or padded.

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 one-parameter pure function this is nearly complete, and it helpfully signals a side output ('list the extracted indicators') in the absence of an output schema. It stops short of describing the return shape or behavior on text with no indicators, which would fully close the gap.

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?

With 100% schema coverage on a single parameter, the schema already documents 'text' including the 64 KB limit. The description adds no additional semantics about the input beyond naming the indicator types, so the baseline of 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 (defang) and enumerates the exact resource types handled (URLs, IPv4, emails, domains), plus concrete transformation examples (hxxp://, [.], [@]). It doesn't explicitly name the reverse sibling refang_iocs, but the verb itself is unambiguous enough that an agent can distinguish the pair.

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?

The phrase 'so they are safe to paste into tickets or chat' gives a concrete use case and context, which is clear guidance about when this tool applies. There is no explicit exclusion or named alternative (e.g., 'use refang_iocs to reverse'), so it falls short of a 5.

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