VanityNumbers.com

See who has held a toll free number

number_history

Read-onlyIdempotent

See a toll free number's history from Resporgs.com: which RespOrgs (the companies that manage toll free numbers) have held it and when, and its status in each span, from the toll free registry's records. Use it when someone asks who had a toll free number before, or how long it has been with its current company. Returns the current holder, each earlier span, newest first, and a link to the number's page on Resporgs.com.

Input Schema

Name	Required	Description	Default
`email`	No	Optional: the person's email, if they have a confirmed notification with VanityNumbers.com. The lookup is then connected to their notifications, so their emails' suggestions fit what they're looking for.
`number`	Yes	A toll free number, by digits or spelling, like 800-356-9377 or 1-800-FLOWERS.

Output Schema

Name	Required	Default
`note`	No
`page`	Yes
`as_of`	No
`label`	Yes
`number`	Yes
`source`	No
`contact`	No	Questions? Bill Quimby, 1-800-MARKETER (1-800-627-5383).
`current`	No
`history`	No
`summary`	No
`data_through`	No
`earlier_spans`	No

Schema Changelog

Changes observed during successful MCP inspections.

Changed1 schema field changedOct 19, 2026

changedInput schema / properties / email / description

Previous value: -"Optional: the person's email, if they have a confirmed watch with VanityNumbers.com. The lookup is then connected to their watch, so its emails' suggestions fit what they're looking for."New value: +"Optional: the person's email, if they have a confirmed notification with VanityNumbers.com. The lookup is then connected to their notifications, so their emails' suggestions fit what they're looking for."

Changed1 schema field changedOct 18, 2026

addedInput schema / properties / email

Added value: +{
+  "anyOf": [
+    {
+      "type": "string"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "description": "Optional: the person's email, if they have a confirmed watch with VanityNumbers.com. The lookup is then connected to their watch, so its emails' suggestions fit what they're looking for.",
+  "title": "Email"
+}

First observedOct 16, 2026

TDQS

A4.1/5.0

Behavior4/5

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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so safety is covered. The description adds real behavioral context beyond that: data comes from the toll free registry's records, spans are returned newest first, and a Resporgs.com link is included.

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

Conciseness4/5

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

One tight paragraph, front-loaded with the resource and output shape, then the use case, then return details. Slightly redundant with the title's 'who has held a toll free number', but nothing is wasted.

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

Completeness4/5

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

With a full output schema and complete annotations, the description only needs to establish purpose and usage, which it does. The remaining gap is sibling disambiguation among the five other number tools.

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 both parameters (number formats, and the optional email/notification linkage) are documented in the schema itself. The description adds no parameter-level detail, so the baseline 3 applies.

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?

States a specific verb and resource ('see a toll free number's history') and enumerates exactly what is returned: RespOrgs that held it, time spans, and status per span. The registry/Resporgs.com sourcing distinguishes it from siblings like check_number (current status) or search_vanity_numbers.

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

Usage Guidelines4/5

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

Gives clear triggering conditions ('who had a toll free number before', 'how long it has been with its current company'). It stops short of naming an alternative tool or a when-not condition, e.g. pointing to check_number for current-owner questions, which would matter given six siblings.

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

All VanityNumbers.com tools Inspect

Try in Browser

One endpoint for every MCP toolRayrun runs every MCP server behind one URL and holds the credentials. Each call is decided per client, tool, and argument, then recorded.ray.runAd

Glama MCP Gateway

Add one secure layer between your agents and this server.

Resources

Need Help?