Scan files with YARA rules to detect packers, anti-debugging, and other signatures; omit rules_file to use the bundled detection pack.
Run YARA rules; without rules_file the bundled packer/anti-debug pack is used.
| Name | Required | Description | Default |
|---|---|---|---|
| path | Yes | ||
| rules_file | No |
Changes observed during successful MCP inspections.
v0.3.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries full burden. It discloses the default rule pack, which is useful, but omits read-only safety, permissions, output format, and performance characteristics. This leaves significant behavioral gaps.
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 with zero waste: purpose is front-loaded, followed by the key default behavior. 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?
For a simple scan tool with no output schema and no annotations, the description covers purpose and default rules but omits what the scan returns (matches, format) and scope limits. It is adequate but not fully complete.
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 0%, so the description must compensate. It adds valuable meaning for rules_file (defaults to bundled packer/anti-debug pack) but does not explain the path parameter. Partial compensation warrants a 3.
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 specific verb+resource: 'Run YARA rules'. It also clarifies the default rule pack when rules_file is omitted. However, it does not differentiate from sibling tools like yara_pack or strings_scan, so a 4 rather than 5.
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 only guidance is the implicit condition for using the bundled pack when rules_file is absent. There is no explicit when-to-use versus alternatives, no prerequisites, and no exclusions.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.