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qc_maf_filter

Assess markers by minor-allele frequency and missingness, generating a CSV report of variants that would fail thresholds. Preview filtering effects before applying changes, without modifying the dataset.

Instructions

Report markers that would be filtered by MAF / missingness (no changes applied).

Computes per-marker minor-allele frequency and missing rate, and counts how many markers are monomorphic, below maf_threshold, or above max_missing missing. Writes marker_filter_stats.csv. This is a report only — it does not modify Gigwa. For large sets pass method="allelematrix" + max_markers to sample server-side.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
methodNoGenotype source: 'vcf' (full export, cached) or 'allelematrix' (paged, server-side subset).vcf
regionNoRestrict analysis to a genomic window: 'chrom' or 'chrom:start-end' (1-based).
output_dirNoDirectory for the output CSV(s) (default ./gigwa_results/<module>/).
max_markersNoCap analysis to the first N markers in canonical Gigwa search order; omit to use all.
max_missingNoMaximum per-marker missing-data fraction (0-1) before a marker is flagged.
maf_thresholdNoMinor-allele-frequency threshold below which markers are flagged.
variant_set_db_idYesBrAPI variantSetDbId identifying the run (MODULE§project§run) -- copy the exact string from list_variant_sets / list_content, never assemble one by hand: the middle segment is a numeric project index, not the project's name, and a wrong guess fails with an opaque HTTP 500 rather than a clear error.

Output Schema

TableJSON Schema
NameRequiredDescriptionDefault
resultYes

Schema Changelog

Changes observed during successful MCP inspections. Dates show when Glama detected each change.

  1. Changed2 schema fields changedv1.9.1
    • changedInput schema / properties / max_markers / description
      Previous value: -"Cap the number of markers analysed (evenly-spaced subsample); omit to use all."New value: +"Cap analysis to the first N markers in canonical Gigwa search order; omit to use all."
    • changedInput schema / properties / variant_set_db_id / description
      Previous value: -"BrAPI variantSetDbId identifying the run (MODULE§project§run); from list_variant_sets / list_content."New value: +"BrAPI variantSetDbId identifying the run (MODULE§project§run) -- copy the exact string from list_variant_sets / list_content, never assemble one by hand: the middle segment is a numeric project index, not the project's name, and a wrong guess fails with an opaque HTTP 500 rather than a clear error."
  2. First observedv1.4.16

TDQS

A4.5/5.0
Behavior5/5

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

With no annotations provided, the description carries the full burden, and it succeeds: it explicitly states 'no changes applied', 'this is a report only — it does not modify Gigwa', and discloses the file output (marker_filter_stats.csv). It also explains the sampling behavior for large sets. This is comprehensive behavioral disclosure for a read-only QC reporting tool.

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 compact, front-loaded with the core purpose, and every sentence earns its place: purpose, computation details, side-effect disclosure, and scale guidance. There is no redundant or filler content.

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

Completeness5/5

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

Given the tool has 7 parameters and no annotations, the description is complete enough for an agent to select and invoke it correctly: it explains what is computed, what file is written, that no data mutation occurs, and how to handle large sets. The output schema covers return structure, so return-value details are not needed in the description.

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 description coverage is 100%, so the baseline is 3. The description adds some contextual meaning by associating method and max_markers with a server-side sampling strategy for large sets, but it does not substantially enrich the already-detailed parameter descriptions in the schema.

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 opens with a specific verb and object: 'Report markers that would be filtered by MAF / missingness (no changes applied).' It clearly distinguishes the tool from sibling QC tools by naming the exact computation (MAF and missing rate) and the report-only nature.

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

Usage Guidelines4/5

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

The description provides clear context for when to use the tool — to preview MAF and missingness filtering without modifying data — and gives concrete guidance for large data sets (method='allelematrix' + max_markers). It does not name alternative sibling tools or state explicit exclusions, but the 'report only' framing and scale guidance are strong usage signals.

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

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