datalineage-bigquery-asset-impact-analysis

SKILL.md

BigQuery Asset Impact Analysis

This skill guides the agent in performing a downstream impact analysis (blast
radius assessment) when a BigQuery table or view is reported as broken, stale,
missing, or when a user is planning maintenance and wants to know the
consequences of modifying or pausing updates to an asset.

It relies primarily on the data lineage (Knowledge Catalog) MCP Server on
Google Cloud to discover relationships between assets.

Prerequisites

This skill requires access to the data lineage API on Google Cloud and an active
client connection to the Data Lineage MCP Server. For detailed connection
configurations and tool schemas, refer to MCP Usage.

Analysis Workflow

1. Resolve the Asset's Fully Qualified Name (FQN)

Ensure you have the correct FQN format for the BigQuery asset:

Format: bigquery:{project_id}.{dataset_id}.{table_or_view_id}

Example: bigquery:my-prod-project.analytics.orders

2. Determine Locations and Parent Path

Identify the locations to search and construct the Data Lineage API request:

Discover Asset Location: Run the command bq show --format=json {project_id}:{dataset_id} and extract the location field (e.g.,
us-central1 or us). If location discovery fails due to permissions or
missing tools, prompt the user for the dataset's location.

Set Parent Path: Set the parent path using the project ID and the
MCP server's location. Consult the DataLineageServer tool definition
to find the configured region or location (e.g., us). The format is:
projects/{project_id}/locations/{mcp_server_location}.

Configure Search Scope: Include the discovered asset location in the
locations array of the payload (e.g., ["us-central1"] or ["us", "us-central1"]).

3. Retrieve the Downstream Lineage Graph

Call the DataLineageServer:search_lineage tool to fetch downstream
relationships.

Direction: Set to DOWNSTREAM.

Search Parameters: Use max_depth = 10 and max_process_per_link = 5
as robust defaults.

4. Identify the Blast Radius

Traverse the returned lineage links to build the impact graph:

Affected Assets: The target of each link represents a downstream asset
that depends on your source asset.

Transform Processes: Inspect the processes field on each link. This
identifies the ETL pipelines, BigQuery Views, or Scheduled Queries that
propagate the data.

Direct vs. Indirect Impact:

Direct Impact (Depth 1): Assets directly consuming the source asset.
If a link has dependency_type: EXACT_COPY, mark the target as
"Directly Stale / Identical Copy".

Indirect Impact (Depth > 1): Assets further down the stream that
will experience cascading stale data or failures.

5. Summarize and Format the Output

Present your findings clearly to the user using the following structure:

Executive Summary: State the total number of downstream assets affected
and the maximum depth of the impact.

Critical Path: Highlight high-priority downstream assets (e.g., assets
containing "prod", "dashboard", "reporting", or "master" in their names).

Blast Radius Table: A clean Markdown table listing the dependencies. You
MUST include all columns:

Downstream Asset
Transform Process
Depth
Impact Type

bigquery:project.dataset.table
projects/p/locations/l/processes/proc
1
Direct

bigquery:project.dataset.view
projects/p/locations/l/processes/view
2
Indirect

Analysis Metadata: Provide transparency on the parameters and boundaries
of your search so the user can choose to expand them:

Locations Searched: {list_of_locations_queried}

Parent Location: {parent_path}

Depth Limit: {max_depth}

Process per Link Limit: {max_process_per_link}

Tip for User: Let the user know they can request to rerun the analysis
with expanded locations or larger depth limits.

Crucial Constraints & Guardrails

Interpret Empty Responses Correctly:

If the lineage response is empty, immediately assume that no
dependencies exist in the queried locations and report this to the
user.

Strictly Banned Bypasses:

Exclusively retrieve downstream relationships using the
DataLineageServer:search_lineage tool.

Verify Asset Existence First:

If bq show indicates the source table does not exist, stop and report
this directly to the user. Do not attempt to guess alternative table
names unless the user explicitly instructs you to do so.

No Output Shortcutting or Hallucinated Artifacts:

Present the complete downstream blast radius table directly in your
final response. Avoid telling the user you have created a separate
Markdown file or artifact containing the details unless you have
explicitly executed file-writing tools to create it.

Reference Directory

MCP Usage: Using the data lineage remote MCP
server on Google Cloud and tool preferences.

External Documentation

Knowledge Catalog Data Lineage Documentation

Use the Data Lineage MCP server

Knowledge Catalog Data Lineage API Reference