The Nothing

Fetch (Nothing)

fetch

Read-onlyIdempotent

Retrieve an empty document for any ID to prototype, demo, test, or dry-run AI workflows without connecting to real data sources.

Instructions

Fetches nothing. Returns an empty document for any id, because nothing is stored here.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "id": "<id>"
    },
    "name": "fetch"
  }
}

Input Schema

Name	Required	Description	Default
`id`	Yes	Document id. Every id resolves to nothing.

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.0Oct 31, 2026

TDQS

A3.7/5.0

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 behavior. The description adds the key behavioral fact that no data exists and every call returns an empty document, which is the essential thing to know. It's still thin on the exact shape of the empty return, but that's minor for a no-op.

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?

Two short sentences, front-loaded with the no-op fact and followed by the reason. Every clause earns its place with zero filler.

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?

For a single-parameter stub tool with no output schema, the description fully covers both the input behavior (any id works) and the return value (empty document). An agent has everything needed to call it correctly.

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 coverage is 100% and the id parameter is already described as resolving to nothing, so the description's 'any id' statement largely restates the schema. Baseline 3 is appropriate when the schema does the work.

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

Purpose4/5

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

The description names a specific verb (fetches) and states its exact effect: returns an empty document for any id because nothing is stored. That's unambiguous and distinguishes it from 'search' and 'pass_through' in intent, though it doesn't explicitly contrast with those siblings.

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

Usage Guidelines2/5

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

It never says when to use this tool versus the siblings (nothing, pass_through, search), nor does it explicitly warn agents away from it for real retrieval. The no-op nature is heavily implied but no alternative routing is given.

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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