You found a broken dropdown on staging. You want your AI coding agent to fix it. The question is what you hand it: a still frame with a note that says "the menu overlaps the header at 1280px," or a 40-second recording where you talk through the same thing while your cursor wanders. Both capture the problem. They do not land the same way once an agent has to read them.
The short version: a recording is richer for a human watching in real time, and a still capture with written notes is far easier for an agent to act on. The right choice depends on who is on the receiving end and what they need to do next. The full comparison of screen capture and screen recording covers the general case; here the focus is narrow, agent input specifically.
What an agent can actually read
An AI coding agent does not watch video. It reads text. A recording is a stream of pixels over time, and to feed it to an agent you first have to convert it into something textual: a transcript, a summary, a set of extracted frames. Every conversion loses detail and adds a step you have to do by hand.
A still capture with a typed or dictated comment is already text plus one image. The comment says what is wrong. The screenshot shows the state. A numbered pin ties the note to a spot on the screen. That is the whole payload, and it maps directly to what the agent needs to change a line of code. This is why a Loom video does not work as agent input without a lot of manual transcription first.
Consider the difference in a real handoff. A recording forces the agent, or you, to answer "at what timestamp does the bug appear, and what exactly was said about it?" A still frame answers both before the agent reads a word: the frame is the moment, the comment is the instruction.
Where a recording still wins
A recording is the honest choice when timing is the bug. An animation that stutters, a loading spinner that never resolves, a race condition that only shows up after three fast clicks, a scroll jank you cannot freeze into one frame. A still cannot hold motion, so if the defect is motion, a recording captures what a screenshot cannot.
A recording is also better when you are demonstrating a flow to a person who will watch it, not to an agent that will parse it. Onboarding a new teammate, walking a client through a prototype, showing support how a customer hit an edge case. In those cases the human watching benefits from the narration and the continuity.
But notice the pattern: the recording wins when a human is the receiver and time is part of the message. The moment the receiver is a coding agent, the recording's strengths turn into overhead.
Comparing the two on what decides the choice
| Dimension | Still capture with notes | Screen recording |
|---|---|---|
| Agent can read it directly | Yes, it is already text plus an image | No, needs transcription or frame extraction first |
| Captures motion and timing | No | Yes |
| Precision of the instruction | High, a note pinned to a spot | Lower, narration spread across seconds |
| Receiver skims quickly | Yes, scan the note | No, must watch in real time |
| Effort to produce | Low, capture and type | Low to record, high to make usable for an agent |
For most UI bugs, layout, copy, color, spacing, a missing state, a wrong label, the defect is visible in a single frame. That is the large majority of feedback that reaches a coding agent, and the still capture is the cleaner input every time.
How to get a still capture into a shape an agent reads
The gap between "I have a screenshot" and "my agent can act on this" is the format. A raw PNG dropped in a chat is not much better than a video; the agent still has no words to work from. What closes the gap is the note attached to the image and the format you export.
In Cobalt Capture you open a browser tab, click Capture screen, and the current frame is drawn to a canvas. You crop to the part that matters, drop a numbered pin on the broken element, and type or dictate the comment. Each capture becomes an item. When you publish, the review gets a public link a person can open, and the same review is available as clean markdown a coding agent reads at the /markdown path. No install, no extension, no signup. It is free.
That markdown is the piece that matters for agent input. It carries your note, the pin reference, and the image together in the plain text an agent parses without a conversion step. If you want the mechanics, turning a screen capture into clean markdown walks through it end to end.
Which one to reach for
Send a still capture with notes when the bug is visible in one frame and a coding agent is doing the fix. That covers most UI feedback. Send a recording when the defect is timing or motion, or when a person is going to watch it and learn a flow. And if you are trying to build a fast feedback loop for vibecoding, default to stills, because every recording you send is a transcription task you have quietly assigned to yourself.
Not sure which your case is? Ask one question: does the problem still exist if you pause the screen? If yes, a still capture says it faster. Start a review and hand your agent the markdown.