validate_config
Validate a 3TG configuration object (.3tg.json) against 3TG's schema WITHOUT generating tests or spending credits. Use this whenever you or the user has hand-edited .3tg/config.3tg.json (or a per-source .3tg/<source>.md.3tg.json) — it catches the mistakes that would otherwise surface as confusing...
This record as markdown: /tools/dev-3tg-mcp/validate-config.md
What validate_config does on 3TG Test Generation
AI agents call validate_config to retrieve information from 3TG Test Generation without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
| Parameter | Type | Required | Description |
|---|---|---|---|
config | object | Yes | The parsed 3TG configuration object to validate — the JSON contents of `.3tg/config.3tg.json` or a `.md.3tg.json` file. The agent reads the file from disk, pars |
Parameters from the server's own tool schema.
Why validate_config is rated Low
This tool is a read-only validation/check operation. It examines a configuration file against a schema and reports errors without modifying files, executing code, or triggering test generation. It has no side effects—it purely retrieves and analyzes the structure of the configuration object to report validation results.
From the tool's definition Tool description states it performs validation and checking WITHOUT generating tests or spending credits. The verb 'validate' combined with 'catches mistakes' indicates pure schema verification against a configuration object with no side effects, data…
Attacks that exploit this kind of access
The rule that runs validate_config safely
PolicyLayer is an MCP gateway: it sits between your AI agents and 3TG Test Generation, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For validate_config, this is the rule to start with:
validate_config is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect 3TG Test Generation, apply this rule, and every validate_config call is checked against it from then on.
Questions about validate_config
Validate a 3TG configuration object (.3tg.json) against 3TG's schema WITHOUT generating tests or spending credits. Use this whenever you or the user has hand-edited .3tg/config.3tg.json (or a per-source .3tg/<source>.md.3tg.json) — it catches the mistakes that would otherwise surface as confusing failures at generation time. WHAT IT CATCHES (via 3TG's -C check-config pass): - a value of the wrong type (e.g. mock-parameters set to a string instead of an object); - an unknown / misspelled key, including invalid rule names (e.g. rules.string.no-emppty or a no-such-rule); - any other Draft-7 schema violation. This complements the 3tg://schema/config resource: read that resource to discover the valid keys; call this tool to actively verify a concrete config before saving it. This tool is FREE — no clientId, no quota. On failure, problems lists the exact schema-violation lines 3TG reported; surface them to the user and help fix the config, then re-validate. A valid: true result means the config is structurally accepted by 3TG (it does not assert the values are semantically ideal for any particular source file). It is categorised as a Read tool in the 3TG Test Generation MCP Server, which means it retrieves data without modifying state.
validate_config accepts 1 parameter: config. Required: config. The full parameter table on this page comes from the server's own tool schema.
Register the 3TG Test Generation MCP server in PolicyLayer and add a rule for validate_config: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches 3TG Test Generation. Nothing to install.
validate_config is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the validate_config rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for validate_config. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
validate_config is provided by the 3TG Test Generation MCP server (https://mcp.3tg.dev/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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