defend_searchFind D3FEND countermeasures by defensive tactic or identify ATT&CK techniques mitigated by a named countermeasure.
List D3FEND countermeasures, optionally filtered by defensive tactic, or find which ATT&CK techniques a named countermeasure applies to.
| Name | Required | Description | Default |
|---|---|---|---|
| limit | No | ||
| tactic | No | ||
| countermeasure | No | Name to look up affected techniques for |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the behavioral burden. It discloses two operational modes and the optional tactic filter, but it does not describe what happens when both tactic and countermeasure are supplied, the output shape, or pagination/limit behavior. This is acceptable for a read/list tool but leaves edge cases undisclosed.
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, front-loaded with the primary action and optional filter, with no wasted words. It conveys the full range of functionality compactly while remaining readable.
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 tool with three optional parameters and no output schema, the description is minimally adequate for selecting and starting to use the tool. However, it does not describe the return format, default behavior when no filters are provided, or how limit applies, so an agent could not fully predict the result of a call.
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 only 33% (only countermeasure has a schema description). The tool description adds meaning by connecting tactic to 'defensive tactic' filtering and countermeasure to 'named countermeasure' technique lookup, but it does not explain the limit parameter or how the parameters interact when combined.
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 clear dual purpose: list D3FEND countermeasures optionally filtered by tactic, or resolve a named countermeasure to the ATT&CK techniques it applies to. This is specific about verb, resource, and scope, and differentiates it from ATT&CK-focused siblings and the plain defend_countermeasures tool.
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 description makes the tool's context clear: use it when browsing D3FEND countermeasures by tactic or when you need technique mappings for a specific countermeasure. It does not explicitly name sibling alternatives or say when not to use them, but the D3FEND scope and lookup mode are sufficiently explicit.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.