Retrieves the FIRST.org EPSS 30-day probability that a given CVE will be exploited in the wild, helping you prioritize vulnerability remediation by real-world risk.
FIRST.org Exploit Prediction Scoring System 30-day real-world CVE exploit probability score.
| Name | Required | Description | Default |
|---|---|---|---|
| cve | Yes | Common Vulnerabilities and Exposures ID (e.g. 'CVE-2024-3094') |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already state readOnlyHint=true, openWorldHint=true, and destructiveHint=false, so the safety profile is covered externally. The description adds the meaningful semantic detail that the number is a 30-day real-world exploit probability, but says nothing about the value's scale, whether scores are cached or refreshed daily, or how unknown CVEs are handled.
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 front-loaded sentence with no filler. It is efficient, though its brevity borders on under-specification for an agent that needs to know what the returned score looks like.
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?
The tool is simple, but with no output schema the description is the only place to learn what is returned (a 0–1 probability, a percentile, a date) and it does not say. It is adequate to select the tool but incomplete for interpreting the result.
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 100% and the single 'cve' parameter is documented with a concrete example in the schema. The description adds no additional parameter meaning, so the baseline 3 applies.
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 resource and metric: the FIRST.org EPSS 30-day exploit probability for a CVE. An agent can tell this is a lookup of a specific external score rather than a general CVE audit, though it does not explicitly distinguish itself from the sibling security_cve_audit.
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?
There is no guidance on when to use this tool versus security_cve_audit or any other CVE-related sibling, and no prerequisites (e.g., valid CVE ID format, whether unknown CVEs return a default). Usage is only implied by the tool's name and subject matter.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.