Writing a prompt that resolves

Operation, reference, number. Drop one and the instruction has nothing to resolve against.

The rule

An instruction resolves when it contains three things:

The operation. Fillet, cut, pattern, shell, export, generate. Not "improve" or "clean up".
The reference. Which face, which feature, which holes, which components. A live selection in SOLIDWORKS counts as a reference.
The number. The dimension, count, spacing, or angle. "Bigger" is not a number.

A fourth thing sits outside the sentence: the mode. Only Agent and Drawings can change the model, so a perfectly written edit sent from Ask Mode comes back as That would change your model. Switch to Agent mode to build or edit it.

Rewriting an instruction that does not resolve

Make it lighter → Shell the part to 2.5 mm, keeping the mounting bosses solid: The first has no operation and no reference. The second names the operation, the wall, and the exception.
Fix the corners → Add a 1 mm fillet to every edge under 2 mm radius on the top face: The first has no selection rule. The second gives a rule that resolves to a specific edge set, and lands as one fillet feature rather than one per edge.
Make the holes bigger → Change the four Ø6 through holes on the flange to Ø8 and keep the counterbores concentric: The first is ambiguous about which holes and by how much. The second states count, current size, new size, and the downstream rule.
Add some ribs → Add 3 mm ribs from the central boss to the outer wall, patterned 8 times about the axis: The second gives the rib thickness, where it runs, and the pattern count.
Tidy the drawing → Dimension the bore and add a section view through it on sheet 1: The second names two operations and what each acts on. Both are Drawings Mode work.
Send me a PDF → Export this part as a PDF to C:\Users\you\Documents\bracket.pdf: The second names the format and an absolute path. A relative path, a .. segment, or a bare drive root is refused. See getting a file out.
It broke → Rebuild and tell me why Cut-Extrude3 is failing: The second is a Debug Mode request. Debug reads the metadata and the feature list, forces a rebuild with diagnostics, and checks external references before it answers.

Referring to things reliably

The most reliable reference is a live selection. Select the face, edge or feature in SOLIDWORKS and say "this face". The current selection is read on every prompt, so nothing else has to identify it.

The second most reliable is a name that exists in the feature tree, spelled the way the tree spells it: Cut-Extrude3, not "the slot cut".

Every prompt also carries the document name, type, path, active configuration, configuration count and units, whether you are in a sketch, the feature count, any rollback, an assembly summary, and up to 12 features currently in error or warning. Parts and assemblies add a digest of up to 60 features, up to 16 custom properties, and a geometry block of bounding box, mass, volume, material and body count. How a prompt is answered covers the rest.

A description like "the big hole" resolves when there is exactly one candidate and fails when there are three. When you are not sure, ask first: which features could you mean by the mounting holes.

Units, precision, and standing instructions

Units and precision, Millimeters or Inches and 0 to 4 decimal places, reaches the model as an instruction on every turn. It does not change the SOLIDWORKS document unit setting, and it is not applied to Drawings Mode turns, which follow the learned drawing standard instead.

It is one account value with two front ends: the task pane Settings and the dashboard preferences write the same setting, so changing it in either place changes it on every machine you sign in on.

State the unit in the prompt anyway. 3 mm cannot be misread; 3 can.

Anything you would otherwise repeat every turn belongs in Modeling standards, one free-text field of up to 60,000 characters that is prepended to your requests. It is cached for five minutes, so an edit made on another machine can take that long to take effect. Modeling rules covers what to put in it.

Match the verb to the mode

The mode picker is a pill in the composer. There is no keyboard shortcut and no mode setting in Settings, and the mode you used last is remembered per machine.

Ask answers and cannot edit. When the answer implies a change it offers a Run in Agent button on the reply.
Plan writes a plan of 4 to 10 steps and performs none of it. The plan carries a Build this button that switches the composer to Agent and runs it.
Agent performs the change, and is the only mode that writes an exported file.
Drawings generates and edits drawings, and rebuilds a print as a part. If a drawing is the active document, every prompt routes here whatever mode is selected.
Debug forces a rebuild before answering and never edits.
Imagine proposes concepts; Pick one to model it rewrites the turn into Agent Mode and builds it.

Sending in a mode your plan does not carry never reaches the service. The transcript answers <Mode> mode isn’t available on your current plan. with an upgrade link. Plans and limits lists which plan carries which.

Keep one instruction to one outcome

Chain unrelated requests instead, and check the model between them. A long turn also re-checks your credit allowance before each model call, so a run that outlives the allowance stops part way.

The exception is a deliberate batch. "Drawings for every part in this assembly" is one outcome expressed once.

When you are unsure the instruction will resolve the way you read it, send it in Plan Mode first. The plan names the features it intends to touch before anything is touched.