Analyze JWT tokens to identify security flaws, test for signature bypasses, and validate token handling against common vulnerabilities.
JWT security testing
| Name | Required | Description | Default |
|---|---|---|---|
| url | No | ||
| token | Yes | ||
| dry_run | No | Preview commands/steps without executing the scan | |
| session_id | Yes |
Changes observed during successful MCP inspections.
v3.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations provided, and the description does not disclose any behavioral traits such as destructive actions, authentication needs, or output format. The agent cannot infer what the tool does beyond minimal testing.
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?
The description is only two words, which is under-specification rather than conciseness. It lacks any structure or details, making it insufficient for an agent to understand the tool.
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?
Given 4 parameters, no output schema, and no annotations, the description is severely incomplete. It provides no context on how to use the tool, what results to expect, or any prerequisites.
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 description adds no parameter information. With only 25% schema description coverage (one parameter documented in schema), the description should compensate but does not explain the role of 'url', 'token', or 'session_id'.
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 'JWT security testing' is vague; it does not specify the exact operation (e.g., decode, crack, scan) and fails to differentiate from other potential JWT tools. A more precise verb+resource would clarify its purpose.
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?
No guidance on when to use this tool versus siblings like sqlmap or nmap. The agent has no context for appropriate use cases or when to choose this tool over alternatives.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.