Function compact_tool_description 

pub fn compact_tool_description(
    original: &str,
    mode: ToolDocumentationMode,
    per_tool_max: Option<usize>,
) -> String

Project a tool description for the given documentation mode.

• Minimal: first sentence without its terminal period, at most MINIMAL_DESCRIPTION_MAX_CHARS.
• Progressive: whole leading sentences within PROGRESSIVE_DESCRIPTION_MAX_CHARS.
• Full: the complete description.

per_tool_max (used for MCP tools) further lowers the limit in every mode. Whitespace runs are collapsed to single spaces in all modes.