add-new-tool.md

How to add a tool ?

1. Look at ./src/tools/readFile.ts for an example
2. Create a new file ./src/tools/<camelCaseToolName>.ts
3. Write and export an interface for your tool args
   • Create the input validation schema using zod
   • Create the type infering it from the schema
   • Export the tool as default export, complying with the Tool interface from ./src/tool.utils.ts
   • Make sure the tool name matches the file's name