Ferret

Put a label on something

attach_label

Assign an existing Ferret QR label or external code to an item, box, or location so scanning it opens that record.

Instructions

Puts a label the household already has on an item, a box or a place, so scanning it opens that: one of their blank Ferret QR labels (its 6-character code, e.g. K7QM2X) or — on items and boxes — any other code, like an asset tag or a sticker from elsewhere. Use it when the person says "I stuck label K7QM2X on the camping bin". Give itemId or locationId, not both. Refused if the label is already on something, or the thing already has a Ferret label.

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": {
      "code": "<code>"
    },
    "name": "attach_label"
  }
}

Input Schema

Name	Required	Description
`code`	Yes	The label's code as printed or scanned
`itemId`	No	The item or box, from search_inventory
`locationId`	No	The place, from list_locations

Schema Changelog

Changes observed during successful MCP inspections.

Addedv2026.11.6Nov 6, 2026

TDQS

A4.5/5.0

Behavior4/5

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

Annotations only declare write/non-destructive/non-open-world; the description adds real behavioural detail beyond them — the two refusal conditions, which are effectively idempotency and uniqueness guards the agent can pre-check. It also implies an asymmetry not visible in the schema: non-Ferret codes are only valid on items and boxes, not places. It stops short of describing the success response or any permission requirements.

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?

Purpose and effect are front-loaded, then code types, then the trigger example, then the parameter constraint and refusals — a sensible order with no filler sentences. The middle clause is dense with em-dashes and parentheticals, which makes it slightly harder to scan than it needs to be.

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?

For a 3-parameter mutation tool with no output schema, the description covers what it does, which inputs are valid, and when it fails. The only material gap is what a successful call returns or confirms, which matters because there is no output schema to fall back on.

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

Parameters4/5

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

Schema coverage is 100%, so the baseline is 3, but the description adds meaning the schema cannot express: the mutual exclusivity of itemId and locationId (the schema has no oneOf), the concrete format of code (6 characters, e.g. K7QM2X), and the fact that arbitrary barcodes are acceptable for items and boxes. That is genuine value on top of the field descriptions.

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 gives a specific verb and resource ("puts a label the household already has on an item, a box or a place") and immediately states the effect ("so scanning it opens that"). It also enumerates the two accepted code classes — a blank Ferret QR label's 6-character code, or any other code on items/boxes — which distinguishes it from neighbours like lookup_barcode or create_item.

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?

It supplies a concrete natural-language trigger ("I stuck label K7QM2X on the camping bin"), an explicit parameter rule ("Give itemId or locationId, not both"), and explicit when-not conditions ("Refused if the label is already on something, or the thing already has a Ferret label"). An agent has everything needed to decide for or against calling it.

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