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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint=false and destructiveHint=false, so the safety profile is fully covered structurally. The description adds only that tag values come with descriptions and that the risk scale is explained, which is modest extra context; it says nothing about output size or how the taxonomy is versioned. With annotations carrying the behavioral load, a 3 is appropriate.

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 sentences, zero filler: the first enumerates what is returned and the second states the intended use, with the enumeration front-loaded. Every clause earns its place.

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?

An output schema exists, so the description is not obliged to describe return values and instead summarizes the four content areas at a useful level. For a zero-parameter, read-only reference tool this covers everything an agent needs 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?

The tool takes zero parameters, so there is nothing for the description to disambiguate and the baseline of 4 applies. The description correctly does not waste space on parameter discussion.

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 names a specific verb ("List") plus four concrete resource categories (IOC types, IOC tags with descriptions, IOC categories, export formats) and adds an explanatory component (the false-positive risk scale). That is far more specific than the title alone and no sibling tool covers reference enumeration, so an agent can identify it unambiguously even without an explicit contrast sentence.

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?

"Use these values for the filters of the search and list tools" tells the agent exactly when to reach for this tool: before filtering via search_iocs, search_reports, list_report_iocs, etc. It gives clear positive guidance but no exclusions or caveats about when this tool is unnecessary.

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