[Simple] Tool Calls do not work if no newline is given at start

[linsaftw]

Description

Example:

Let me search for the fetch method properly:<tool_call>
<function=grep>
<parameter=-A>
10
</parameter>
<parameter=output>
content
</parameter>
<parameter=path>
/home/linsaftw/Downloads/scraper/scraper/fetcher/adaptive.py
</parameter>
<parameter=pattern>
async def fetch
</parameter>
</function>
</tool_call>

Solution A: Instruct the prompt to always add new lines before tool calls.
Solution B: Decode tool calls that do not have new lines before them.

Plugins

None

OpenCode version

1.2.24

Steps to reproduce

It happens randomly when using Step 3.5

Screenshot and/or share link

No response

Operating System

Kubuntu 25.10 (Docker w/debian)

Terminal

Konsole

[github-actions]

This issue doesn't fully meet our contributing guidelines.

What needs to be fixed:

• Steps to reproduce are missing — please provide a minimal sequence of steps to trigger the issue
• OpenCode version, Operating System, and Terminal fields are all empty — this context is needed to investigate the bug

Please edit this issue to address the above within 2 hours, or it will be automatically closed.

---

This issue might be a duplicate of existing issues. Please check:

• retry invalid tool-call diff / malformed tool input instead of aborting #15906: retry invalid tool-call diff / malformed tool input instead of aborting (related to malformed/unparseable tool calls)
• Tool execution aborted when tool call is truncated (empty input) #13102: Tool execution aborted when tool call is truncated (empty input) (similar tool call parsing failure)

If you believe this was flagged incorrectly, please let a maintainer know.

[linsaftw]

If I tell the model to add a new line, it works all the time.

[linsaftw]

[LeoNardo-LB]

Samissue and mark