verification-practice: what it makes your agent do, and what it refuses.

verification-practice is the method that makes a system prove a figure rather than show it: reconciliation to a total the file states, two independent reads, refusals that carry an exit code, and gate tests proved by sabotage rather than by existing. It came out of an audit that found six fatal defects in a mature engine.

The job verification-practice does

Every defect this method was built on was a false pass or a silent data loss, never a crash and never a wrong looking page, which is why reading the code did not find them. The moves are cumulative. Tie each published figure to a total the source itself states, and label a file that asserts none as unverified rather than inventing a check. Compute the number twice down paths that share nothing, all the way through parsing and date handling. Refuse when the input is ambiguous, with an exit code a pipeline can read. Then prove each gate by breaking the code behind it and watching that exact row turn red, because a check nobody has seen fail is a comment with a runtime cost.

What verification-practice refuses

A skill is worth what it stops as much as what it produces. These are the refusals written into verification-practice, taken from the rules and limits in its own file.

✓A check that has never been seen to fail. Every gate needs a captured red run through the production path, produced by sabotaging the code behind it.
✓Two paths that are really one. If both reads call the same parse for a field, the disclosure says so and that field counts as a single read.
✓A tolerance on a count. A count matches or it does not, and a default tolerance of one absorbs exactly the dropped record it exists to catch.
✓Guessing past an ambiguity. The build refuses, names the file and the damage it would have done, and states that nothing was changed.
✓A period filter that half sums an anchor. Whole anchored units are excluded or the build refuses, never rows from inside one.

9 lines from the verification-practice skill file, verbatim

From skills/verification-practice/SKILL.md, unedited. Kymira skills are plain text you can read in full before you install them, which is the point of shipping a method rather than a binary.

A verified number is one that reconciles to a total **the source file
itself states**: a totals row, a stated base, a printed grand total. That
is the only check a vendor cannot argue with. Corollary: a file that
states no totals cannot have verified figures — publish them **labelled
unverified**, and say why, rather than inventing a check or hiding the
doubt.

- A tolerance is denominated in the value's own display unit.
- **A count gets no tolerance** — it matches or it doesn't. A default

The failure modes verification-practice addresses

These entries in the catalogue of 51 observed failure modes name this skill as what addresses them. Every one was seen in a real build or in our own audits, and none was invented.

The wrong column that reconcilesThe number is plausible, and wrong The join that quietly covers 62%The file lies The verify script that silently did nothingThe verification is theater The check that cannot failThe verification is theater Borrowed evidenceThe verification is theater Both rails from one blueprintThe verification is theater The tolerance that ate the errorThe verification is theater The tie that compared revenue to seatsThe verification is theater The check that reads its own configurationThe verification is theater The manifest that contradicts its pageThe wrapper betrays the numbers The blocked run that ate the good packThe wrapper betrays the numbers

The tier verification-practice ships in

Tier	Price	What the tier holds	verification-practice
Free	$0	honest-dataviz and the eleven doctrine principles, published in full	Not in this tier
Core Pack	$199	the thirteen craft skills, one-time purchase, lifetime updates	Included
Everything	$349	all 22 skills, both libraries, the template bank, one-time purchase, lifetime updates	Included

Both paid tiers are a one-time purchase with lifetime updates, and all sales are final: the files are plain text you keep the moment they arrive, so judge the quality on the free skill and the published doctrine first. The pricing section states exactly what each tier contains.

Installing verification-practice

A skill is a folder with a SKILL.md file in it. Installing one is copying that folder where your agent looks for skills, with no build step and no dependencies.

mkdir -p ~/.claude/skills
cp -R Kymira/skills/verification-practice ~/.claude/skills/

Or open the unzipped pack in Claude Code and say install Kymira, which installs every skill in your tier, or double-click the installer for your system. Cursor reads the same skill as a rule file: copy verification-practice.mdc into .cursor/rules/. Skills are read at startup, so start a new session and ask your agent which skills it has available.

Not for

It proves arithmetic, not meaning. A figure can tie perfectly to the file's own total and still answer the wrong question, because the column was wrong or the word on the label has two live definitions. That gap belongs to contested-metrics, the metric store and period-freshness.

Last updated 2026-08-29 · Dylan, founder · one of 22 packaged skills, each one a method written down, not a product tour.

See the tiers → All 22 skills The doctrine The failure catalogue