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BigQuery Validator

by caron14

mcp-bigquery

Safe BigQuery exploration through Model Context Protocol

MIT License PyPI Version Python Support Downloads

Documentation | Quick Start | Examples


Overview

mcp-bigquery is a Model Context Protocol (MCP) server that enables AI assistants (such as Claude) to interact securely with Google BigQuery.

Key Features

  • Secure execution: All operations are strictly limited to dry-run verification. The server never executes queries that mutate data or incur execution costs.

  • Cost transparency: Provides estimates of query costs and processed bytes before execution.

  • Static analysis: Analyzes query dependencies and validates SQL syntax.

  • Schema exploration: Browses datasets, tables, and columns.

Business Value

Problem

Solution with mcp-bigquery

Unintentional execution of costly queries

Pre-execution cost estimation

Delayed development due to SQL syntax errors

Early syntax error detection

Lack of visibility into schema structures

Secure schema metadata discovery

Risk of unauthorized data mutation by AI

Enforced dry-run constraints


Related MCP server: mcp-bigquery-dryrun

Quick Start

Step 1: Installation

Install the package via pip:

pip install mcp-bigquery

Step 2: Authentication

Set up Google Cloud Platform authentication:

# For user account authentication
gcloud auth application-default login

# For service account authentication
export GOOGLE_APPLICATION_CREDENTIALS=/path/to/key.json

Step 3: Claude Desktop Configuration

Configure the server in the Claude Desktop configuration file:

  • macOS: ~/Library/Application Support/Claude/claude_desktop_config.json

  • Windows: %APPDATA%\Claude\claude_desktop_config.json

Add the following entry:

{
  "mcpServers": {
    "mcp-bigquery": {
      "command": "mcp-bigquery",
      "env": {
        "BQ_PROJECT": "your-gcp-project-id"
      }
    }
  }
}

Step 4: Verification

Restart Claude Desktop and run the following queries to verify the setup:

  • "What datasets are available in my BigQuery project?"

  • "Can you estimate the cost of: SELECT * FROM dataset.table"

  • "Show me the schema for the users table"


Available Tools

SQL Validation and Analysis

Tool

Purpose

Primary Use Case

bq_validate_sql

Check SQL syntax

Verification prior to query execution

bq_dry_run_sql

Retrieve cost estimates and metadata

Pre-execution cost assessment

bq_extract_dependencies

Map table dependencies

Lineage and dependency mapping

bq_validate_query_syntax

Detailed syntax analysis

Debugging complex SQL queries

Schema Discovery

Tool

Purpose

Primary Use Case

bq_list_datasets

List all datasets in the project

Initial project discovery

bq_list_tables

List tables with partitioning metadata

Dataset structure browsing

bq_describe_table

Get detailed schema details

Column-level verification

bq_get_table_info

Retrieve comprehensive metadata

Table statistics analysis

bq_preview_table

Preview table data (cost-free)

Checking sample records without data scan costs

IMPORTANT

Thebq_preview_table tool uses client.list_rows (API: tabledata.list) to retrieve sample rows directly, resulting in zero bytes scanned and no execution costs. To prevent unintended exposure of sensitive information (such as PII) to the LLM, this tool is disabled by default. You must explicitly opt in by setting MCP_BQ_ENABLE_PREVIEW=true in your environment config.


Configuration

Environment Variables

Variable

Purpose

Default

BQ_PROJECT

Target GCP Project ID

Determined via ADC

BQ_LOCATION

Target BigQuery Region

Not set

SAFE_PRICE_PER_TIB

Price per TiB for cost estimation

5.0

LOG_LEVEL

Logging verbosity (DEBUG, INFO, WARNING, ERROR, CRITICAL)

WARNING

MCP_BQ_ENABLE_PREVIEW

Enable the bq_preview_table tool (true/false)

false

Example .env File

For local testing or development environments, you can define these variables in a .env file:

BQ_PROJECT=your-gcp-project-id
BQ_LOCATION=asia-northeast1
SAFE_PRICE_PER_TIB=5.0
LOG_LEVEL=WARNING
MCP_BQ_ENABLE_PREVIEW=true

Complete Claude Desktop Configuration Example

{
  "mcpServers": {
    "mcp-bigquery": {
      "command": "mcp-bigquery",
      "env": {
        "BQ_PROJECT": "my-production-project",
        "BQ_LOCATION": "asia-northeast1",
        "SAFE_PRICE_PER_TIB": "6.0",
        "LOG_LEVEL": "WARNING",
        "MCP_BQ_ENABLE_PREVIEW": "true"
      }
    }
  }
}

Troubleshooting

Mapped Errors and Solutions

Authentication Error

Error: Could not automatically determine credentials
  • Solution: Re-authenticate using the command line:

    gcloud auth application-default login

Permission Denied

Error: User does not have bigquery.tables.get permission
  • Solution: Grant the BigQuery Data Viewer role to the target identity:

    gcloud projects add-iam-policy-binding YOUR_PROJECT \
      --member="user:your-email@example.com" \
      --role="roles/bigquery.dataViewer"

Project ID Missing

Error: Project ID is required
  • Solution: Ensure the BQ_PROJECT variable is set correctly in your configuration.


Examples of Usage

Example 1: Check Costs Before Running

# Before running an expensive query...
query = "SELECT * FROM `bigquery-public-data.github_repos.commits`"

# First, check the cost
result = bq_dry_run_sql(sql=query)
print(f"Estimated cost: ${result['usdEstimate']}")
print(f"Data processed: {result['totalBytesProcessed'] / 1e9:.2f} GB")

# Output:
# Estimated cost: $12.50
# Data processed: 2500.00 GB

Example 2: Understand Table Structure

# Check table schema
result = bq_describe_table(
    dataset_id="your_dataset",
    table_id="users"
)

# Output:
# ├── user_id (INTEGER, REQUIRED)
# ├── email (STRING, NULLABLE)
# ├── created_at (TIMESTAMP, REQUIRED)
# └── profile (RECORD, REPEATED)
#     ├── name (STRING)
#     └── age (INTEGER)

Example 3: Track Data Dependencies

# Understand query dependencies
query = """
WITH user_stats AS (
  SELECT user_id, COUNT(*) as order_count
  FROM orders
  GROUP BY user_id
)
SELECT u.name, s.order_count
FROM users u
JOIN user_stats s ON u.id = s.user_id
"""

result = bq_extract_dependencies(sql=query)

# Output:
# Tables: ['orders', 'users']
# Columns: ['user_id', 'name', 'id']
# Dependency Graph:
#   orders → user_stats → final_result
#   users → final_result

Project Status and Version History

Version

Release Date

Summary of Changes

v0.7.1

2026-08-17

Refined mcp dependency constraints and streamlined wiki documentation

v0.7.0

2026-06-21

Added cost-free table preview tool (bq_preview_table) and security opt-in configuration

v0.6.0

2026-06-21

Thread-safe caching, recursive AST queries, backoff retries, and Google API exception mapping

v0.5.0

2026-01-02

Consolidated formatters, client cache, and unified logging controls

v0.4.2

2025-12-08

Modular schema explorer and unified client/logging controls

v0.4.1

2025-01-22

Error handling and debug logging improvements

v0.4.0

2025-01-22

Added schema discovery tools

v0.3.0

2025-01-17

Integrated SQL static analysis engine

v0.2.0

2025-01-16

Initial release supporting basic validation and dry-run queries


Development and Contribution

For instructions on local development setup and contribution policies, please refer to the CONTRIBUTING.md guide.

# Clone the repository
git clone https://github.com/caron14/mcp-bigquery.git
cd mcp-bigquery

# Install development dependencies
pip install -e ".[dev]"

# Execute the test suite
pytest tests/

License

This project is licensed under the MIT License. See LICENSE for details.

Available Tools

9 tools
bq_describe_tableB

Get table schema, metadata, and statistics

ParametersJSON Schema
NameRequiredDescriptionDefault
table_idYesThe table ID
dataset_idYesThe dataset ID
project_idNoGCP project ID (uses default if not provided)
format_outputNoWhether to format schema as table string

TDQS

B3.3/5.0
Behavior3/5

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

With no annotations, the description carries the full burden. It correctly implies a read-only operation ('Get') and lists output categories (schema, metadata, statistics), but does not disclose permissions, latency, or data freshness. Adequate but not detailed.

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?

The description is a single sentence that front-loads the verb and resource. Every word contributes meaning with zero waste.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness3/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple read tool with a well-documented input schema and no output schema, the description gives a high-level summary but lacks specifics on the return format, field details, or how it differs from similar siblings. It meets minimum viability.

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?

All 4 parameters are fully documented in the input schema (100% coverage). The description adds no extra parameter semantics beyond the schema descriptions, so baseline 3 applies.

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 clearly states the verb 'Get' and the resource 'table schema, metadata, and statistics'. However, it does not differentiate from sibling tool 'bq_get_table_info', which likely has overlapping functionality.

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?

The description provides no guidance on when to use this tool versus alternatives like 'bq_get_table_info' or 'bq_list_tables'. It lacks when-not-to-use or context for selection.

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

bq_dry_run_sqlA

Perform a dry-run of a BigQuery SQL query to get cost estimates and metadata

ParametersJSON Schema
NameRequiredDescriptionDefault
sqlYesThe SQL query to dry-run
paramsNoOptional query parameters (key-value pairs)
pricePerTiBNoPrice per TiB for cost estimation (defaults to env var or 5.0)

TDQS

A3.6/5.0
Behavior3/5

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

The description indicates a dry-run is performed, implying no actual execution or data modification, but it does not disclose permissions needed or behavior for invalid queries. With no annotations, the description carries the full burden and is adequate but not exhaustive.

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?

The description is a single, succinct sentence that conveys the core purpose without unnecessary words. It is optimally concise.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness2/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The description lacks details about the output format and metadata provided. With no output schema, the description should explain what cost estimates and metadata are returned. It also omits behavioral context like error handling or permission requirements.

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?

All parameters are described in the input schema with 100% coverage. The description adds no additional meaning beyond the schema, so a baseline score of 3 is appropriate.

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 performs a dry-run of a BigQuery SQL query to get cost estimates and metadata. The verb 'dry-run' and resource 'SQL query' are specific, and the purpose is distinct from sibling tools like bq_validate_query_syntax.

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

Usage Guidelines3/5

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

The description implies the tool should be used when one needs cost estimates and metadata before executing a query, but it does not explicitly state when to use it versus alternatives, nor does it provide exclusions or prerequisites.

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

bq_extract_dependenciesC

Extract table and column dependencies from BigQuery SQL

ParametersJSON Schema
NameRequiredDescriptionDefault
sqlYesThe SQL query to analyze
paramsNoOptional query parameters (key-value pairs)

TDQS

C2.9/5.0
Behavior2/5

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

With no annotations provided, the description must fully disclose behavioral traits. It does not mention whether the tool executes the query, is read-only, requires permissions, or has side effects. 'Extract' implies reading but it is not explicit.

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?

The description is a single concise sentence with no redundant information. Every word is necessary.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness2/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The tool extracts dependencies but provides no output schema, leaving the agent uninformed about the return format. Given the complexity of dependencies (tables, columns), the description is too sparse.

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 schema already describes both parameters. The description adds no additional meaning beyond the schema, so baseline score of 3 is appropriate.

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 uses the specific verb 'Extract' and the resource 'table and column dependencies from BigQuery SQL', making the action clear. It implicitly distinguishes from siblings like bq_validate_query_syntax, but does not explicitly differentiate.

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?

No guidance on when to use this tool versus alternatives (e.g., bq_validate_sql). The description lacks any context about appropriate use cases or exclusions.

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

bq_get_table_infoB

Get comprehensive table information including partitioning and clustering

ParametersJSON Schema
NameRequiredDescriptionDefault
table_idYesThe table ID
dataset_idYesThe dataset ID
project_idNoGCP project ID (uses default if not provided)

TDQS

B3.1/5.0
Behavior2/5

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

With no annotations, the description must carry the full burden of behavioral transparency. It mentions the tool is a 'get' operation but does not disclose auth requirements, error handling, or whether it is read-only. The inclusion of partitioning and clustering adds some output context but not behavioral traits.

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?

The description is a single, front-loaded sentence that states the tool's purpose without any wasted words. It is maximally concise while still conveying essential information.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness3/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple information-retrieval tool with three parameters and no output schema, the description provides the core purpose and hints at output content (partitioning, clustering). However, it lacks details on error behavior, output format, and differentiation from siblings, making it adequate but incomplete.

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?

Input schema has 100% description coverage, so baseline is 3. The description does not add any extra meaning to the parameters beyond the schema, as it focuses on the output instead.

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 clearly states the tool retrieves comprehensive table information including partitioning and clustering. However, it does not explicitly distinguish itself from the sibling tool bq_describe_table, which likely has overlapping functionality.

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?

No guidance is provided on when to use this tool versus alternatives like bq_describe_table. The description lacks any usage context or prerequisites.

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

bq_list_datasetsB

List all datasets in the BigQuery project

ParametersJSON Schema
NameRequiredDescriptionDefault
project_idNoGCP project ID (uses default if not provided)
max_resultsNoMaximum number of datasets to return

TDQS

B3.1/5.0
Behavior2/5

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

No annotations provided. The description lacks behavioral details such as pagination, rate limits, or error handling. The claim 'List all datasets' is contradicted by the max_results parameter, which limits results.

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?

Single sentence without fluff, but could be more informative about behavior. It is efficient but slightly under-specified.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness2/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

No output schema, so description should explain return format. It does not. Lacks context on when to use vs siblings like bq_list_tables. Insufficient for an agent to fully understand the tool's role.

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 descriptions cover 100% of parameters with clear meanings. The description adds no extra value beyond the schema, meeting the baseline but not exceeding it.

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 verb 'List' and the resource 'datasets in the BigQuery project', distinguishing it from siblings like bq_list_tables which list tables instead.

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?

No guidance on when to use this tool vs alternatives (e.g., bq_list_tables for tables). Missing context on prerequisites or suitable scenarios.

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

bq_list_tablesA

List all tables in a BigQuery dataset with metadata

ParametersJSON Schema
NameRequiredDescriptionDefault
dataset_idYesThe dataset ID
project_idNoGCP project ID (uses default if not provided)
max_resultsNoMaximum number of tables
table_type_filterNoFilter by table types (TABLE, VIEW, EXTERNAL, MATERIALIZED_VIEW)

TDQS

A3.7/5.0
Behavior3/5

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

No annotations provided, so the description bears full burden. It states the operation is a listing with metadata but omits behavioral details like pagination, rate limits, or whether it requires specific permissions. It is not misleading but leaves gaps.

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?

Single sentence of 8 words, front-loaded with purpose. Every word earns its place; no wasted text.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness3/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Tool has no output schema. Description says 'with metadata' but does not specify what metadata fields are returned. For a list operation, this is adequate but not complete. Parameters are well-documented, but return value details are missing.

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?

Input schema has 100% coverage with descriptions for all 4 parameters. The description adds no extra meaning beyond 'with metadata', which hints at return content. Baseline is 3 since schema already provides clarity.

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 'List all tables in a BigQuery dataset with metadata', specifying the verb 'list', resource 'tables', and scope 'in a BigQuery dataset'. It distinguishes itself from siblings like bq_describe_table and bq_get_table_info effectively.

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

Usage Guidelines3/5

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

No explicit guidance on when to use this tool vs alternatives (e.g., bq_list_datasets lists datasets, not tables). The description implies usage for listing tables with metadata but doesn't provide when-not or exclusion criteria.

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

bq_preview_tableB

Get a preview of table data without running a query job (cost-free)

ParametersJSON Schema
NameRequiredDescriptionDefault
table_idYesThe table ID
dataset_idYesThe dataset ID
project_idNoGCP project ID (uses default if not provided)
max_resultsNoMaximum number of rows to preview (default: 5, hard limit: 10)

TDQS

B3.4/5.0
Behavior2/5

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

No annotations are present, so the description must fully disclose behavior. It mentions cost-free and no query job, but fails to describe return format (e.g., rows), ordering (first rows?), or the hard limit of 10 from the schema. This omission leaves significant behavioral unknowns.

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?

A single, front-loaded sentence with zero wasted words. It efficiently conveys purpose and key differentiator.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness2/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given no output schema, the description should explain return values (e.g., 'returns first N rows as JSON') but does not. It also omits details like permission requirements or that preview uses the first rows. The tool is simple, but the description is incomplete for safe invocation.

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% with all parameters described in the schema. The description adds no extra meaning beyond summarizing the schema. Thus baseline 3 is appropriate.

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 action ('preview table data') and key benefit ('cost-free, without running a query job'). It distinguishes from siblings like bq_describe_table (schema) and bq_run_query (costly query). This provides a specific verb+resource with differentiation.

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

Usage Guidelines3/5

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

The description implies use for quick, cost-free previews but lacks explicit when-not or alternative tools. With siblings including bq_get_table_info and bq_dry_run_sql, no comparison or exclusion is provided, leaving guidance implicit.

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

bq_validate_query_syntaxC

Enhanced syntax validation with detailed error reporting

ParametersJSON Schema
NameRequiredDescriptionDefault
sqlYesThe SQL query to validate
paramsNoOptional query parameters (key-value pairs)

TDQS

C2.5/5.0
Behavior2/5

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

No annotations provided, so description carries full burden. It claims 'detailed error reporting' but does not explain what constitutes enhanced behavior, side effects, or limitations. Lacks any behavioral context beyond a vague promise.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness3/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is very short (one phrase), but it is front-loaded with functionality. However, it sacrifices necessary detail for brevity, making it less helpful.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness2/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a tool with no output schema and two parameters, the description should explain what 'enhanced' validation entails, expected error messages, or usage examples. It fails to provide sufficient context for effective use.

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% with adequate parameter descriptions. The tool description adds no additional parameter-specific meaning, achieving only baseline value.

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

Purpose3/5

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

The description states 'syntax validation' which implies validating SQL syntax, but does not explicitly mention SQL queries. The phrase 'enhanced...with detailed error reporting' adds some clarity but fails to distinguish from sibling tool 'bq_validate_sql'.

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?

No guidance on when to use this tool versus the similar sibling 'bq_validate_sql'. The description offers no context for selection.

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

bq_validate_sqlB

Validate BigQuery SQL syntax without executing the query

ParametersJSON Schema
NameRequiredDescriptionDefault
sqlYesThe SQL query to validate
paramsNoOptional query parameters (key-value pairs)

TDQS

B3.1/5.0
Behavior2/5

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

No annotations are provided, so the description must fully convey behavior. It only states the tool validates syntax without execution, but it does not disclose what happens upon invalid syntax, permissions required, or whether it checks only syntax or also semantics.

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?

The description is a single, clear sentence with no wasted words. However, it could be slightly expanded to address sibling differentiation.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness2/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the lack of output schema and annotations, the description should explain what the tool returns (e.g., valid/invalid with errors). It also fails to distinguish from a similarly named sibling, leaving the agent potentially confused.

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 baseline is 3. The description adds no additional meaning beyond the schema's existing parameter descriptions for 'sql' and 'params'.

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 clearly states it validates BigQuery SQL syntax without execution. However, it does not differentiate from the sibling tool 'bq_validate_query_syntax', which appears to have the same purpose.

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

Usage Guidelines3/5

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

The description implies it is safe to use for validation (no execution), but it provides no explicit guidance on when to use this tool versus the similar 'bq_dry_run_sql' or 'bq_validate_query_syntax'.

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

Tool Schema Changelog

Recent tool additions, removals, and schema changes observed during successful MCP inspections. Dates show when Glama detected each change.

  1. 1 tool updatev0.7.0
    • Addedbq_preview_table
  2. 4 tool updatesv0.2.1
    • Removedbq_analyze_query_performance
    • Removedbq_analyze_query_structure
    • Changedbq_list_tables1 field changed
      • changedInput schema / properties / max_results / description
        Previous value: -"Maximum number of tables to return"New value: +"Maximum number of tables"
    • Removedbq_query_info_schema
  3. 9 tool updatesv1.0.0
    • Addedbq_analyze_query_performance
    • Addedbq_analyze_query_structure
    • Addedbq_describe_table
    • Addedbq_extract_dependencies
    • Addedbq_get_table_info
    • Addedbq_list_datasets
    • Addedbq_list_tables
    • Addedbq_query_info_schema
    • Addedbq_validate_query_syntax
  4. 2 tool updates
    • First observedbq_dry_run_sql
    • First observedbq_validate_sql

TDQS

B3.2/5.0
Disambiguation3/5

Some tools have overlapping purposes, such as bq_describe_table and bq_get_table_info both providing table metadata, and bq_validate_query_syntax and bq_validate_sql both validating SQL. While descriptions help differentiate, there is potential for agent confusion.

Naming Consistency4/5

All tools follow the bq_verb_noun pattern with underscores. Verbs like 'list', 'validate', and 'describe' are consistent, though 'dry_run' and 'extract' differ slightly. The naming is mostly predictable.

Tool Count5/5

With 8 tools, the server covers essential BigQuery validation and metadata operations without being sparse or bloated. Each tool serves a clear purpose within the domain.

Completeness4/5

The tool set covers core validation (syntax, dry-run, dependencies) and metadata exploration (datasets, tables, schemas). Minor gaps exist, such as dataset-level metadata, but overall the surface is adequate for the validator purpose.

Maintenance

ActivityMaintained
ResponsivenessNo issues

Resources

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