Query returns results when running it individually, returns an ambiguous reference when I add it to a larger query

I am trying to write a query that summarizes vulnerabilities by host name, and includes information about that host. Query is running in Rapid7 InsightVM

The query that returns asset information runs successfully, except when I append that query to return vulnerability information it returns an ambiguous reference error for description. But the ip address, host_name, and asset_id values returns just fine.

I am just trying to combined them together to return that information. I feel like something obvious is missing.

This returns what I want from the asset table including the OS Description (Windows, RHEL, etc):

SELECT da.asset_id, da.host_name, da.ip_address, dos.description
FROM dim_asset da
JOIN dim_operating_system dos ON dos.operating_system_id = da.operating_system_id
JOIN fact_asset fa ON fa.asset_id = da.asset_id
GROUP BY da.asset_id, da.host_name, da.ip_address, dos.description

This returns an ambiguous reference for the description, it works for asset_id, host_name, and ip_address:

    WITH remediations AS (
        SELECT DISTINCT fr.solution_id AS ultimate_soln_id, summary, fix, estimate, riskscore, dshs.solution_id AS solution_id
        FROM fact_remediation(10,'riskscore DESC') fr
        JOIN dim_solution ds USING (solution_id)
        JOIN dim_solution_highest_supercedence dshs ON (fr.solution_id = dshs.superceding_solution_id AND ds.solution_id = dshs.superceding_solution_id)

    ),

    assets AS (
        SELECT da.asset_id, da.host_name, da.ip_address, dos.description
        FROM dim_asset da
        JOIN dim_operating_system dos ON dos.operating_system_id = da.operating_system_id
        JOIN fact_asset fa ON fa.asset_id = da.asset_id
        GROUP BY da.asset_id, da.host_name, da.ip_address, dos.description
    )

    SELECT
       csv(DISTINCT dv.title) AS "Vulnerability Title",
       host_name AS "Asset Hostname", ip_address AS "Asset IP", description AS "OS",
       round(sum(dv.riskscore)) AS "Asset Risk",
       summary AS "Solution",
       fix as "Fix"

    FROM remediations r
       JOIN dim_asset_vulnerability_solution dvs USING (solution_id)
       JOIN dim_vulnerability dv USING (vulnerability_id)
       JOIN assets USING (asset_id)

    GROUP BY r.riskscore, host_name, ip_address, asset_id, summary, fix
    ORDER BY "Asset Risk" DESC     WITH remediations AS (

Most likely, dim_asset_vulnerability_solution or dim_vulnerability also have a description field. Just qualifying the selected fields with their intended source should resolve this problem.

...
a.host_name AS "Asset Hostname", a.ip_address AS "Asset IP", a.description AS "OS"
...
JOIN assets AS a USING (asset_id)
...
GROUP BY r.riskscore, a.host_name, a.ip_address, asset_id, summary, fix

Note: asset_id is not a problem because USING has some extra "magic" that merges the references joined by it.

Comment: Unless there are very specific reasons, GROUP BY should not be used as a substitute for SELECT DISTINCT (referring to the assets CTE in particular)