The body is well-organized and avoids concept-explaining fluff, but the sheet-selection/missing-input logic is restated three times (Missing-input policy, the in-template 'Sheet selection and missing inputs', and 'Required behavioral rules'), so not every token earns its place.

Provides concrete name/description patterns, a full copy-paste system-prompt template, exact refusal wording, explicit completion criteria, and a full worked example — fully actionable guidance.

Clear build sequence with explicit validation checkpoints: the 'NOT done until' completion checklist, verify-by-read-back feedback loop, and dry-run→confirm gating for destructive operations.

No bundle files exist and sections are well-organized, but the ~120-line body is monolithic — the full system-prompt template and worked example are inline content that could be split into one-level-deep referenced files.

Lists multiple concrete actions — 'updates rows, reads cells, computes totals, generates reports from sheets, syncs data between spreadsheets' — matching the multiple-specific-actions anchor rather than the domain-plus-some-actions level.

Explicitly answers both what ('Authoring playbook for building agents that read or write tabular data…') and when ('Use this when the user wants an agent that…'), with an explicit trigger clause.

Strong natural-term coverage ('Google Sheets, Microsoft Excel, CSV, Airtable, Notion databases', 'rows, columns, ranges, or worksheets') that users would actually say, beyond the some-keywords-missing-common-variations level.

Targets a clear niche (tabular-data agent authoring) with distinct triggers unlikely to fire for non-spreadsheet skills.