billy-mcp

list_products

Read-only

Search, filter, and list products in Billy to retrieve product IDs for creating invoice lines.

Instructions

List products in Billy. Use this to find a product ID before creating invoice lines. Supports free-text search.

Tool call template

This tool declares no required parameters. Add optional parameters from the input schema as needed.

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

Input Schema

Name	Required	Description
`q`	No	Free-text search on product name/number
`page`	No	Page number (1-based)
`verbose`	No	Return the full Billy response. Default false: compact records with key fields only (saves ~90% context)
`pageSize`	No	Records per page (max 1000, default 50)
`productNo`	No	Filter by exact product number
`isArchived`	No	When true, returns only archived records; when false, only active ones

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.3.0Jul 8, 2026

TDQS

A4/5.0

Behavior3/5

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

Annotations already declare readOnlyHint=true, so the description adds limited behavioral context. Mention of free-text search is helpful but does not disclose rate limits, pagination specifics, or the compact vs verbose detail (which is only in schema).

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 sentences with zero waste. Front-loaded with the core action and purpose.

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 list tool with no output schema, the description is adequate. It covers the primary use case and search capability. Could mention that it returns compact records by default (but that detail is in schema).

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%, so the description adds little beyond what the schema provides. 'Free-text search' maps to the 'q' parameter, but the description does not explain other parameters like 'page', 'pageSize', 'verbose', etc.

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?

Description clearly states the action ('List products'), the resource ('products in Billy'), and the use case ('find a product ID before creating invoice lines'). It distinguishes from sibling tools like 'create_product' or 'get_product'.

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?

Explicitly tells when to use the tool ('before creating invoice lines') and mentions support for free-text search. No explicit exclusion of alternatives, but the context is clear enough.

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