Add skill discovery and loading

packages/core/tool-skill/src/index.ts

@@ -0,0 +1,52 @@
+/**
+ * Model-facing `skill` tool.
+ *
+ * @module @deepseek-ai/dsh-tool-skill
+ */
+
+import type { Context } from 'cordis'
+import { defineTool } from '@deepseek-ai/dsh-tools'
+import { isSkillName, type SkillDefinition } from '@deepseek-ai/dsh-skill'
+
+export const name = 'tool-skill'
+export const inject = ['tools', 'skills']
+
+export function apply(ctx: Context): void {
+  const skillTool = defineTool({
+    name: 'skill',
+    description: 'Load the full instructions for one available skill by name. Use this when the current task matches a skill listed in the system prompt.',
+    parameters: {
+      name: { type: 'string', required: true, description: 'The exact skill name from the available skills list.' },
+    },
+    async execute(args, exec) {
+      if (!isSkillName(args.name)) {
+        throw new Error(`invalid skill name "${args.name}"`)
+      }
+      const skill = await ctx.skills.get(args.name, { cwd: exec.agent?.session.header.cwd })
+      if (!skill) {
+        throw new Error(`unknown skill "${args.name}"`)
+      }
+      if (skill.disableModelInvocation === true) {
+        throw new Error(`skill "${args.name}" is not available for model invocation`)
+      }
+      return [{ type: 'text', text: renderSkillContent(skill) }]
+    },
+    presentCall(args) {
+      return { title: `Load skill ${args.name}`, kind: 'read', rawInput: args.name }
+    },
+  })
+  ctx.tools.register(skillTool)
+}
+
+function renderSkillContent(skill: SkillDefinition): string {
+  return [
+    `<skill_content name="${skill.name}">`,
+    `# Skill: ${skill.name}`,
+    '',
+    skill.content,
+    '',
+    `Base directory for this skill: ${skill.directory}`,
+    'Resolve relative files mentioned by this skill against the base directory before using them.',
+    '</skill_content>',
+  ].join('\n')
+}