Required arguments per tool (schemas map in JSON editor).

This page is the SEO reference for the tool_call_args_schema validator. Configure it on an agent in the dashboard or via the agents API. Full catalog: validators.

What it checks

Required arguments per tool (schemas map in JSON editor).

Field	Value
Rule ID	`tool_call_args_schema`
Pack	`code`
Category	Code
Default severity	`error`
Default on_fail	`block`

Config notes

Attach the rule to an agent, set severity and on_fail, then start in shadow mode before enforce. Pack code must be allowed on your plan.

Pass / fail example

Pass: output satisfies the encoded contract for this rule (shape, pattern, or checksum as configured).

Fail: output violates the contract. ValGuard returns a validation failure with this rule ID when on_fail is block or reask.

Exact fixtures depend on your field paths and thresholds. Use the dashboard tester or validate LLM output.

on_fail behaviours

Mode	Effect
`block`	Request fails closed; next step should not run
`reask`	Proxy may retry the model once within plan limits; buffers stream
`warn` / `log`	Traffic continues; audit still records the evaluation
shadow agent	Would-block logged; response still delivered

Prefer fail-closed for money and PHI paths.

Performance

Engine timing: not sampled in the current benchmark snapshot. HTTP path and model time dominate end-to-end latency. See methodology. Numbers are ValGuard's own measurements on published hardware snapshots.

Next step

Quickstart. Attach tool_call_args_schema in shadow on one agent, then enforce.

Tool call args schema: deterministic LLM output check