nofax

Request human approval

nofax_request_approval

Request human approval on a phone for a guarded action, returning a pending requestId to poll until a terminal Allow or Deny. Optionally accept refinement text from the human.

Instructions

Send Allow/Deny to the phone and return a durable pending requestId. IMPORTANT: after this tool returns pending, call nofax_wait_for_response and repeat while it remains pending. Never continue the guarded action without a terminal Allow response. Set allowRefine when the human should also be able to send refinement text.

Input Schema

TableJSON Schema

Name	Required	Description
`title`	No	Optional approval prompt title shown to the human; defaults to "Nofax approval".
`message`	Yes	Guarded action or decision context shown to the human.
`allowRefine`	No	When true, also let the human return free-text refinement instead of only Allow or Deny.

Output Schema

TableJSON Schema

Name	Required	Description
`status`	Yes	The request is unresolved and must not be treated as approval.
`mustWait`	Yes	Signals that the caller must keep waiting for a terminal human response.
`requestId`	Yes	Durable Nofax request handle.
`instruction`	Yes	Fail-closed next-step instruction for the caller.

Schema Changelog

Changes observed during successful MCP inspections.

Changed4 schema fields changedv0.2.7Sep 22, 2026

addedInput schema / properties / allowRefine / description

Added value: +"When true, also let the human return free-text refinement instead of only Allow or Deny."

addedInput schema / properties / message / description

Added value: +"Guarded action or decision context shown to the human."

addedInput schema / properties / title / description

Added value: +"Optional approval prompt title shown to the human; defaults to \"Nofax approval\"."

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "additionalProperties": false,
+  "properties": {
+    "instruction": {
+      "description": "Fail-closed next-step instruction for the caller.",
+      "minLength": 1,
+      "type": "string"
+    },
+    "mustWait": {
+      "const": true,
+      "description": "Signals that the caller must keep waiting for a terminal human response.",
+      "type": "boolean"
+    },
+    "requestId": {
+      "description": "Durable Nofax request handle.",
+      "maxLength": 84,
+      "minLength": 24,
+      "type": "string"
+    },
+    "status": {
+      "const": "pending",
+      "description": "The request is unresolved and must not be treated as approval.",
+      "type": "string"
+    }
+  },
+  "required": [
+    "status",
+    "requestId",
+    "mustWait",
+    "instruction"
+  ],
+  "type": "object"
+}

First observedv0.2.1Sep 21, 2026

TDQS

A4.5/5.0

Behavior4/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already indicate this is not read-only, not idempotent, and not destructive. The description adds valuable behavior beyond those: it returns a durable pending requestId, uses an asynchronous polling pattern, and requires a terminal Allow before proceeding, which is not captured by the annotations alone.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is three sentences with no filler. The critical async workflow is front-loaded with 'IMPORTANT', the terminal-Allow warning is prominent, and the optional flag guidance is placed at the end without redundancy.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The tool has a nontrivial asynchronous approval flow, and the description covers the complete calling pattern: send request, poll with nofax_wait_for_response, repeat while pending, and do not proceed without a terminal Allow. Since an output schema exists, return-value detail is not needed. Nothing essential is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the schema already documents all three parameters. The description reinforces allowRefine ('Set allowRefine when the human should also be able to send refinement text') but does not add substantial new meaning beyond the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb and resource: 'Send Allow/Deny to the phone and return a durable pending requestId'. It clarifies the outcome and distinguishes this from siblings like nofax_request_choice and nofax_request_refinement by mentioning 'allowRefine' and the wait-for-response flow.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines5/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description gives explicit instructions: 'after this tool returns pending, call nofax_wait_for_response and repeat while it remains pending' and 'Never continue the guarded action without a terminal Allow response'. It also states when to set allowRefine, giving the agent clear conditions and workflow.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

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