Add load_skill tool to bypass workspace restriction for builtin skills

When restrictToWorkspace is enabled, the agent cannot read builtin skill
files via read_file since they live outside the workspace. This adds a
dedicated load_skill tool that reads skills by name through the SkillsLoader,
which accesses files directly via Python without the workspace restriction.

- Add LoadSkillTool to filesystem tools
- Register it in the agent loop
- Update system prompt to instruct agent to use load_skill instead of read_file
- Remove raw filesystem paths from skills summary

nanobot/agent/context.py

@@ -46,7 +46,7 @@ class ContextBuilder:
         if skills_summary:
             parts.append(f"""# Skills
 
-The following skills extend your capabilities. To use a skill, read its SKILL.md file using the read_file tool.
+The following skills extend your capabilities. To use a skill, call the load_skill tool with its name.
 Skills with available="false" need dependencies installed first - you can try installing them with apt/brew.
 
 {skills_summary}""")

nanobot/agent/loop.py

@@ -17,7 +17,7 @@ from nanobot.agent.context import ContextBuilder
 from nanobot.agent.memory import MemoryConsolidator
 from nanobot.agent.subagent import SubagentManager
 from nanobot.agent.tools.cron import CronTool
-from nanobot.agent.tools.filesystem import EditFileTool, ListDirTool, ReadFileTool, WriteFileTool
+from nanobot.agent.tools.filesystem import EditFileTool, ListDirTool, LoadSkillTool, ReadFileTool, WriteFileTool
 from nanobot.agent.tools.message import MessageTool
 from nanobot.agent.tools.registry import ToolRegistry
 from nanobot.agent.tools.shell import ExecTool
@@ -128,6 +128,7 @@ class AgentLoop:
         self.tools.register(SpawnTool(manager=self.subagents))
         if self.cron_service:
             self.tools.register(CronTool(self.cron_service))
+        self.tools.register(LoadSkillTool(skills_loader=self.context.skills))
 
     async def _connect_mcp(self) -> None:
         """Connect to configured MCP servers (one-time, lazy)."""

nanobot/agent/skills.py

@@ -118,7 +118,6 @@ class SkillsLoader:
         lines = ["<skills>"]
         for s in all_skills:
             name = escape_xml(s["name"])
-            path = s["path"]
             desc = escape_xml(self._get_skill_description(s["name"]))
             skill_meta = self._get_skill_meta(s["name"])
             available = self._check_requirements(skill_meta)
@@ -126,7 +125,6 @@ class SkillsLoader:
             lines.append(f"  <skill available=\"{str(available).lower()}\">")
             lines.append(f"    <name>{name}</name>")
             lines.append(f"    <description>{desc}</description>")
-            lines.append(f"    <location>{path}</location>")
 
             # Show missing requirements for unavailable skills
             if not available:

nanobot/agent/subagent.py

@@ -213,7 +213,7 @@ Stay focused on the assigned task. Your final response will be reported back to
 
         skills_summary = SkillsLoader(self.workspace).build_skills_summary()
         if skills_summary:
-            parts.append(f"## Skills\n\nRead SKILL.md with read_file to use a skill.\n\n{skills_summary}")
+            parts.append(f"## Skills\n\nUse load_skill tool to load a skill by name.\n\n{skills_summary}")
 
         return "\n\n".join(parts)
 

nanobot/agent/tools/filesystem.py

@@ -363,3 +363,35 @@ class ListDirTool(_FsTool):
             return f"Error: {e}"
         except Exception as e:
             return f"Error listing directory: {e}"
+
+
+class LoadSkillTool(Tool):
+    """Tool to load a skill by name, bypassing workspace restriction."""
+
+    def __init__(self, skills_loader):
+        self._skills_loader = skills_loader
+
+    @property
+    def name(self) -> str:
+        return "load_skill"
+
+    @property
+    def description(self) -> str:
+        return "Load a skill by name. Returns the full SKILL.md content."
+
+    @property
+    def parameters(self) -> dict[str, Any]:
+        return {
+            "type": "object",
+            "properties": {"name": {"type": "string", "description": "The skill name to load"}},
+            "required": ["name"],
+        }
+
+    async def execute(self, name: str, **kwargs: Any) -> str:
+        try:
+            content = self._skills_loader.load_skill(name)
+            if content is None:
+                return f"Error: Skill not found: {name}"
+            return content
+        except Exception as e:
+            return f"Error loading skill: {str(e)}"