Help Text Pattern
Put field guidance in one predictable place, phrased the same way every time.
What it adds
A consistent treatment for the short explanatory text that sits with a field and its control.
What your agent is told to do
5
What your agent is told to do
5-
1
Collect the guidance the app currently scatters across placeholders, tooltips, asterisked footnotes, and modal help, and move it into one slot beneath the field.
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2
Keep guidance that is required to complete the field permanently visible. A format rule hidden behind a hover target is not available to a touch user or a keyboard user.
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3
Write help as the rule the user needs before typing — the accepted format, the consequence of the choice — not as a restatement of the label.
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4
Update conditional guidance when the thing it depends on changes, so a field whose rules differ by country or plan never shows the rule for a different one.
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5
Do not repeat the validation message as help text. Help states the rule in advance; the error states what went wrong, and showing both leaves the user reading the same sentence twice.
Edge cases it handles
7
Edge cases it handles
7- Help that only appears on hover or focus is unreachable on touch and easy to miss with a keyboard; anything essential must be visible at rest.
- Conditional guidance must re-render when its dependency changes and must be announced, or a user who switches country will act on a stale rule that no longer applies.
- When a field becomes invalid, the error takes over as the message the user acts on, but the help must remain associated with the control if it carries the format rule.
- Help text must be programmatically linked to the control, not merely placed near it, or a screen reader user reaches the input with no guidance at all.
- Placeholder text is not help text; it disappears the moment the user types and is invisible to anyone reviewing what they entered.
- Long guidance is a sign the field is wrong — link to documentation rather than growing a paragraph under an input.
- Where this text is rendered and how it is linked belongs to Form Field Shell; this entry owns the wording, the visibility rules, and the conditional behaviour.
Definition of done
8
Definition of done
8- All field guidance appears in the same position relative to the control.
- Guidance needed to complete a field is visible without hover or focus.
- Help text is programmatically associated with its control.
- Conditional guidance updates and is announced when its dependency changes.
- No help text duplicates a validation message.
- No field relies on a placeholder to carry its guidance.
- The feature matches the existing design system.
- No existing functionality is broken.
Related features
Unit Converter
Unit Converter
Let people convert a value between units without leaving the page they are on.
What it does
An inline converter that takes a typed value in one unit and shows the equivalent in another, in place.
How it works
- 1 Start from the units the app actually deals in. A shipping tool needs weight and length; a recipe tool needs volume and temperature. Ship those and leave the rest out.
- 2 Convert as the user types, with the result visible beside the input rather than behind a submit button. Let either side be edited so the conversion runs in both directions.
- 3 Reuse the app's existing number parsing and display formatting rather than writing new ones. If Locale-Aware Numbers and Dates or Number Formatting Component is already present, the converter must render through it so grouping and decimal marks match the rest of the app.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/unit-converter
Field State Matrix
Field State Matrix
Decide once how every field looks and behaves in every state, before screens improvise.
What it does
A defined and documented set of visual and behavioural states covering every input type in the app.
How it works
- 1 Enumerate the app's input types and cross them against every state they can enter: empty, filled, focused, hovered, invalid, valid, disabled, read-only, loading, and browser-autofilled.
- 2 Define disabled and read-only as genuinely different states — a read-only field shows a real value the user may select and copy, a disabled field is inert and excluded from submission.
- 3 Define the loading state so the field is visibly busy and not editable, and say what happens to a keystroke that arrives mid-load rather than letting it be silently swallowed.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/field-state-matrix
Character Limits
Character Limits
Show how much room is left before text gets rejected or cut off.
What it does
Live remaining-character feedback on limited fields, counting the same way the server does.
How it works
- 1 Find every field with a length limit — database column, API constraint, or downstream service — and surface that limit in the UI.
- 2 Count the same units the server counts. If the server counts Unicode characters, do not count UTF-16 code units in the browser; the two disagree on emoji and the user gets rejected for text that looked fine.
- 3 Show remaining count rather than used count once the field is near the limit, and change its emphasis at a threshold rather than colouring it from the start.
Copy the prompt
No account needed
Add this feature to my app:
https://addthisfeature.com/x/character-limits
How it works
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1
Copy the link
Grab the Markdown instruction URL for this feature.
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2
Give it to your AI
Paste it into Claude Code, Cursor, v0, Lovable — whatever you build with.
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3
It inspects, then implements
Your agent reads your existing app first, then adds the feature to fit it.
Works with your stack
These instructions are written to adapt. They tell the agent to detect your framework, match your existing design system, and reuse what you already have — rather than assuming a particular stack.
Need it tighter than that? Customize the feature and tell it exactly what you're running.