Tests whether a URL parameter controls the redirect target to identify open redirect vulnerabilities; use it to validate if user-supplied input can send victims to an external canary URL.
Test whether a parameter controls the redirect target (open redirect).
| Name | Required | Description | Default |
|---|---|---|---|
| url | Yes | ||
| param | Yes | ||
| canary | No | https://pentest-canary.example/landing |
Changes observed during successful MCP inspections.
v0.4.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are supplied, so the description carries the full disclosure burden, and it discloses almost nothing. It does not say that the tool issues live HTTP requests against the target, whether it requires prior scope authorization, how it decides pass/fail, or what the result looks like.
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?
One short sentence with no wasted wording and the key concept front-loaded. The brevity here reflects under-specification rather than disciplined editing, so it is efficient but too sparse to be a strong score.
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 an active web probe with zero schema documentation, no annotations, and no output schema, the definition leaves too much unexplained. An agent cannot determine how to populate the canary parameter or interpret the result without trial and error.
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% across three parameters, so the description needs to compensate and does not. It gestures at "a parameter" and "redirect target" but never explains url (target endpoint), param (name of the query parameter under test), or canary (the default landing URL the redirect is expected to point to and how it is used for detection).
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 action and target: testing whether a parameter controls the redirect target, i.e. an open-redirect probe. That is clearly more informative than the tool name alone. It does not, however, contrast itself with adjacent web probes such as pentest_web_host_header or pentest_web_reflection, which an agent may also consider.
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 reach for this tool versus alternatives, no prerequisites (an in-scope engagement, target reachability), and no exclusions. The agent must infer usage entirely from the tool name and the single sentence.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.