Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100%, so baseline is 3, but the description adds meaning: 'single-cell types' clarifies cellTypesOnly, and naming GTEx/Tabula Sapiens/proteomics concretizes the vague 'gtex, tabula_sapiens and others' source parameter. It does not explain limit ('rows per source'), leaving that to the schema.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.