BigQuery Data Agent only imports 10 Glossaries from Knowledge Catalog (Dataplex) despite column-level links

Google Cloud Data Analytics
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Hello Google Cloud Community / Support Team,

We are currently building a data governance and conversational analytics setup using BigQuery Data Agent integrated with Dataplex Knowledge Catalog.

We have encountered a critical limitation where the Agent only imports and recognizes a maximum of 10 Glossaries from Knowledge Catalog, regardless of how many column-level links (EntryLinks) are configured.

Environment & Setup

  1. Knowledge Catalog (Dataplex): Created a glossary containing over 1,000 Business Terms with detailed Description and Overview attributes.

    knowledge catalog glossary terms
    knowledge catalog glossary terms1754×946 253 KB

  2. Column-Level EntryLinks: Linked these terms to specific columns (e.g., ORDER_QUANTITY) in our target BigQuery table/view (DM_T_BUSINESS_SUMMARY_TRANSACTION_lite_copy_260710_copy).

    glossary related entries column level
    glossary related entries column level794×718 54 KB

  3. Dataplex Auto-Discovery: Asset Discovery is enabled and successfully running (Succeeded).

  4. Verified Behavior: For the 10 terms that do load into the Agent, the Agent successfully reads both Description and Overview attributes (including complex business logic and CASE WHEN statements).

Issue Description

Despite having hundreds of terms linked at the column level, the BigQuery Data Agent UI and backend context retriever strictly limit imported glossaries to 10 items (Glossary (10) / Imported from Knowledge Catalog (10)).

bigquery data agent data source
bigquery data agent data source1749×929 143 KB

data agent only 10 glossary include but the source table contain 199 terms
data agent only 10 glossary include but the source table contain 199 terms1046×525 66.1 KB

data agent glossary detail shows only 10 imported from Knowledge catalog
data agent glossary detail shows only 10 imported from Knowledge catalog1811×926 186 KB

When querying the Agent about a column whose term is linked in Knowledge Catalog but falls outside these 10 imported items (e.g., ALLOWANCE_QUANTITY):

agent cannot refer to the glossary outside of 10
agent cannot refer to the glossary outside of 101817×806 193 KB

  • The background Context Retriever fails to fetch the linked Catalog Term.

  • As a fallback, the Agent attempts to run a SQL query against INFORMATION_SCHEMA.COLUMN_FIELD_PATHS, which fails with: Error: Attempting to access tables outside the conversation's context definition.

  • The Agent then falls back to general LLM inference rather than providing our curated business definitions.

Questions

  1. Is there a default limit parameter (e.g., Top 10 / Preview Limit) on the Context Retriever API when pulling linked EntryLinks into BigQuery Data Agent?

  2. How can we lift or adjust this 10-item limit so that the Agent can dynamically reference all column-linked Glossary Terms across our dataset?

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