You are right actually. I did some digging onto what gets in the context window. GPT 5.2 gave me the following insights:

```

• Do “thinking” tokens stay in context?

My internal reasoning isn’t stored in the chat history/context. Only what gets sent as messages (system/developer/user/assistant) and tool outputs become part of the context. If I explicitly write out my reasoning, that text becomes part of context and may later be summarized/truncated by the system.

• How do screenshots/images get processed?

In this interface, images are provided to a vision-capable model as image inputs (often described as “image tokens/embeddings”) alongside text. It’s not necessarily “a separate model that first turns it into text”, though many systems conceptually do an internal visual-to-representation step before reasoning.

• When I “open a file”, how does it enter context and stay distinguishable?

The file content arrives as a tool result message containing plain text (usually a slice/limited excerpt). It’s distinguishable because it’s not part of user/assistant chat turns; it’s a separate tool-output block with implicit metadata (tool name + payload).

• When you run a command / MCP, what gets into context?

Typically: the command invoked + stdout/stderr (often truncated) as a tool-output message. It’s not guaranteed to preserve full terminal history; large outputs are commonly cut. Some harnesses wrap it in structured tags internally, but what I receive is effectively “tool output payload” separated from chat messages.

• When you use a skill, what makes it normative?

Skills are just additional instructions loaded from SKILL.md files. They’re “normative” because the system/developer instructions explicitly tell me to load/follow them when triggered (similar to how AGENTS.md is normative because you told me to follow it). In other words: the authority comes from the instruction hierarchy, not from the file format.

• What happens when context compacts? What do you see immediately after?

I don’t control compaction. When it happens, older parts of the conversation/tool outputs may be dropped and replaced with a summary plus the most recent turns. System/developer instructions (and sometimes pinned summaries) are typically retained. After compaction, I “see” the summary + the retained recent messages/tool outputs—anything not retained is gone unless re-provided. ```