Function format_capability_index 

pub fn format_capability_index(tools: &[ScoredTool]) -> String

Format retrieved tools as an XML capability index suitable for injection into an agent’s system prompt.

Example output:

<available_capabilities>
  <capability>
    <name>exec</name>
    <category>os-tool</category>
    <description>Execute a shell command in a workspace</description>
  </capability>
  <capability>
    <name>git-helper</name>
    <category>program</category>
    <description>Git workflow automation</description>
    <command>git-helper</command>
    <skill>programs/git-helper/SKILL.md</skill>
  </capability>
</available_capabilities>