If a shell script tool has no arguments, cagent cannot call it

[nicks]

Describe the bug
If a tool has no arguments, cagent cannot call it. I just get a cryptic error

Version affected
v1.7.3

How To Reproduce

Detailed steps to reproduce the behavior:

agent.yaml

#!/usr/bin/env cagent run
version: "2"
agents:
  root:
    model: claude
    description: "tool runner"
    instruction: "you run tools to help repro bugs"
    toolsets:
      - type: script
        shell:
          checkout_repo:
            cmd: "echo hello world"
            description: "checkout a repo and get the message inside"

models:
  claude:
    provider: anthropic
    model: claude-haiku-4-5
    max_tokens: 64000

Run the agent and ask it to run the tool. you will get an error. see screenshot

Expectation

cagent should call the tool

Screenshots

OS and Terminal type

alacritty / linux

[nicks]

when i dug into the code, the tool call arguments were an empty string
https://github.com/docker/cagent/blob/0ff074a0c8c8197a09cdae621caa19f3b94df1f1/pkg/tools/builtin/script_shell.go#L101

[nicks]

i was able to work around this by doing

            args:
              unused:
                description: "unused"
                type: "string"

[rumpl]

Cool, we'll fix it though :)

[dgageot]

Let's reopen it because it now works for:

- type: script
  shell:
    get_ip:
      cmd: "curl -s https://ipinfo.io/ | jq -r .ip"
      description: "Get public IP"

But still not for:

- type: script
  shell:
    checkout_repo:
      cmd: "echo hello world"
      description: "checkout a repo and get the message inside"