This record as markdown: /tools/io-tinyfn-tinyfn/is-valid-url.md
What is_valid_url does on TinyFn
AI agents call is_valid_url to retrieve information from TinyFn without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
| Parameter | Type | Required | Description |
|---|---|---|---|
url | string | Yes | URL to validate |
require_protocol | boolean | — | Require http/https |
Parameters from the server's own tool schema.
Why is_valid_url is rated Low
This tool performs a query or validation check on input data and returns a boolean result without retrieving external data, modifying state, executing code, or causing any side effects. It is purely a data validation utility that conforms to the Read category (query/check operations). Severity is low because misuse would only result in incorrect validation logic, not data loss or compromise.
From the tool's definition Tool name 'is_valid_url' and description 'Validate if a string is a valid URL' indicate a validation/checking operation with no side effects.
Risk signalsAccepts URL/endpoint input (url)
Attacks that exploit this kind of access
The rule that runs is_valid_url safely
PolicyLayer is an MCP gateway: it sits between your AI agents and TinyFn, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For is_valid_url, this is the rule to start with:
is_valid_url is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect TinyFn, apply this rule, and every is_valid_url call is checked against it from then on.
Questions about is_valid_url
Validate if a string is a valid URL. It is categorised as a Read tool in the TinyFn MCP Server, which means it retrieves data without modifying state.
is_valid_url accepts 2 parameters: url, require_protocol. Required: url. The full parameter table on this page comes from the server's own tool schema.
Register the TinyFn MCP server in PolicyLayer and add a rule for is_valid_url: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches TinyFn. Nothing to install.
is_valid_url is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the is_valid_url rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for is_valid_url. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
is_valid_url is provided by the TinyFn MCP server (https://api.tinyfn.io/mcp/all/). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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