Tool calls fail with JSON Parse error when description ends with a dot #24177

Description

When the model emits a tool call (e.g., bash) where the description field ends with a dot (.), OpenCode's text extractor truncates the JSON immediately after that dot. The closing " and } are lost, causing JSON Parse error: Unterminated string or JSON Parse error: Expected '}'

Hypothesis: the pre-parser/regex that extracts JSON tool blocks from the model's raw text splits on sentence boundaries when it sees a dot inside the string value, cutting the JSON mid-object.

Workaround: just force to omit the trailing period in tool description fields. I created a skill for this and it kinda work, except when the model forget the skill.

Environment:

• Model: Kimi 2.6 (via LiteLLM proxy, API OpenAI-compatible)
• OpenCode version: 1.14.23 (from homebrew)
• LiteLLM backend logs: looks clean, the malformed JSON seems generated client-side during text extraction

Plugins

No response

OpenCode version

1.14.23

Steps to reproduce

Just prompt something like "run some bash commands to test" in a fresh opencode session.

An example:

Thinking: The user wants me to run some bash commands to test the system. I should run a few basic commands to test the bash tool functionality. Let me run some simple, non-destructive commands to demonstrate the tool
⚙ invalid [tool=bash, error=Invalid input for tool bash: JSON parsing failed: Text: {"command": "echo \"Hello World\"", "description": "Test basic echo.
Error message: JSON Parse error: Unterminated string]
⚙ invalid [tool=bash, error=Invalid input for tool bash: JSON parsing failed: Text: {"command": "pwd", "description": "Test current directory command.
Error message: JSON Parse error: Unterminated string]

With the skill:

# Show current directory
$ pwd
/Users/nmaillet/Desktop/tmppp
# Display current date
$ date
ven. 24 avr. 2026 16:56:12 CEST

Screenshot and/or share link

No response

Operating System

MacOS26.4.1

Terminal

No response