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why_not

Search & retrieval

Explains why a URL is or is not in the index: present, removed with a reason, or never admitted.

An agent that cannot distinguish "not in the index" from "does not exist" will confidently report the wrong thing. why_not closes that gap.

Removal reasons are typed — redundant, superseded, stale, access-starved, lost-replacement or tombstoned-source — and a superseded passage names its replacement.

Arguments

NameTypeDescription
urlrequiredstringThe URL to explain.

Returns:present, removed with reason and replacement, or unknown.

Example

Prompt: “Why is this documentation page not showing up in results?”

why_not calljson
{ "url": "https://docs.rs/tokio" }

Over HTTP

The same operation is available as GET /why_not for anything that does not speak MCP.

/why_notbash
curl -H "x-api-key: $UNLOB_API_KEY" \
  "https://api.unlob.com/why_not?url=https://docs.rs/tokio"

Setup

One config block gives your client all 11 tools, including this one.

MCP configjson
{
  "mcpServers": {
    "unlob": {
      "command": "npx",
      "args": ["-y", "@unlob/mcp"],
      "env": { "UNLOB_API_KEY": "ulb_your_key_here" }
    }
  }
}

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