Check any URL against PhishTank to see if it is a known phishing site and whether it has been verified. Screen suspicious links before clicking.
Check if a URL is a known phishing site via PhishTank. Returns whether the URL is in their database and if it has been verified.
| Name | Required | Description | Default |
|---|---|---|---|
| url | Yes | URL to check for phishing |
Changes observed during successful MCP inspections.
v0.3.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=true), and the description is consistent with them by naming an external service. It adds useful return semantics (presence in database + verification flag) but omits any mention of latency or rate limits on the PhishTank lookup.
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?
Two tight sentences, front-loaded with the action and source, with zero filler. Nothing could be removed without losing information.
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 one-parameter read-only lookup with no output schema, the description covers the essential return values (membership and verification status). It could say slightly more about the return shape or what an unverified hit means, but it is essentially 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?
There is a single parameter with 100% schema description coverage ('URL to check for phishing'), so the schema carries the semantics. The description adds no format or normalization guidance beyond what the schema already states, making the baseline 3 appropriate.
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?
States a specific verb ('Check'), a specific resource ('a URL'), and the backing data source ('via PhishTank'), which distinguishes it from sibling URL-lookup tools like urlhausLookup. An agent can tell immediately what this does.
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 purpose implies the use case (screening a URL for phishing), but there is no explicit when-to-use guidance, no exclusions, and no pointer to alternatives such as urlhausLookup or pulsedive_indicator for broader URL/indicator checks.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.