LexAPI MCP

Official

Overview Schema Source Related Servers Discussions Admin

lex_search

Search EUR-Lex using free text, date range, document type, author, and language filters. Returns a paginated list of matching documents with CELEX numbers, titles, and dates.

Instructions

Search EUR-Lex with structured filters (free text, date range, document type, author, language). Returns a paginated list of matching documents with CELEX numbers, titles, and dates. Use this when the user wants to find documents matching a topic or filter; use lex_get_document afterwards to fetch full content of a specific result.

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": "lex_search"
  }
}

Input Schema

Name	Required	Description	Default
`query`	No	Free-text search.
`textScope`	No	Where to apply the query string.
`dateFrom`	No
`dateTo`	No
`year`	No
`documentType`	No
`author`	No
`language`	No		en
`maxPages`	No	Result pages to fetch (clamped by subscription tier).

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Jun 25, 2026

TDQS

A4.4/5.0

Behavior4/5

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

With no annotations provided, the description carries full burden. It discloses that the tool returns a paginated list, mentions the result fields, and notes that maxPages is clamped by subscription tier. This adds useful behavioral context beyond a simple search description.

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: first defines the tool and its output, second gives usage guidance. Every word earns its place. Front-loaded with the most critical information.

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?

Given 9 parameters and no output schema, the description covers the main functionality and return format. However, it omits details on pagination behavior (e.g., page size, navigation) and does not elaborate on all parameter constraints. Still, it provides a solid overview.

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?

The description lists the filter categories (free text, date range, document type, author, language) but does not add detailed semantics beyond the schema. Since schema description coverage is only 33%, the description partially compensates by summarizing parameter groups, but lacks specifics on format or values.

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 clearly states the tool searches EUR-Lex with structured filters and returns a paginated list of documents with specific fields (CELEX numbers, titles, dates). It distinguishes itself from the sibling tool lex_get_document by advising to use it afterward for full content.

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?

Explicitly says 'Use this when the user wants to find documents matching a topic or filter; use lex_get_document afterwards to fetch full content of a specific result.' This provides clear when-to-use and alternative guidance.

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

Deploy Server