mask_text

Mask text, keeping only start/end characters visible.

SERVERTinyFn SOURCEhttps://api.tinyfn.io/mcp/all/

Low RISK CLASS

Category Read

Parameters 41 required

Recommended Allowedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/io-tinyfn-tinyfn/mask-text.md

WHAT IT DOES

What mask_text does on TinyFn

AI agents call mask_text 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
`end`	integer	—	Characters to keep at end
`text`	string	Yes	Text to mask
`start`	integer	—	Characters to keep at start
`mask_char`	string	—	Masking character

Parameters from the server's own tool schema.

RISK

Why mask_text is rated Low

This tool performs a deterministic text transformation (masking), returning a modified string. It does not persist data, execute code, or have external side effects. It is a pure read/transform operation similar to encoding or hashing tools on this server.

From the tool's definition 'Mask text, keeping only start/end characters visible' — purely transforms/reads input text, no side effects

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs mask_text 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 mask_text, this is the rule to start with:

mask_text Allowed

mask_text is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "mask_text": {}
  }
}

ALLOW ONLY THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect TinyFn, apply this rule, and every mask_text call is checked against it from then on.

FAQ

Questions about mask_text

What does the mask_text tool do? +

Mask text, keeping only start/end characters visible. It is categorised as a Read tool in the TinyFn MCP Server, which means it retrieves data without modifying state.

What parameters does mask_text accept? +

mask_text accepts 4 parameters: end, text, start, mask_char. Required: text. The full parameter table on this page comes from the server's own tool schema.

How do I enforce a policy on mask_text? +

Register the TinyFn MCP server in PolicyLayer and add a rule for mask_text: 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.

What risk level is mask_text? +

mask_text is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit mask_text? +

Yes. Add a rate_limit block to the mask_text 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.

How do I block mask_text completely? +

Set action: deny in the PolicyLayer policy for mask_text. 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.

What MCP server provides mask_text? +

mask_text 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.

KEEP EXPLORING

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