Skip to main content
Glama

tf_check_arguments

Read-onlyIdempotent

Validate Terraform resource, data, or ephemeral argument and nested-block paths against the pinned provider schema before writing them. Flags unknown, read-only, and deprecated paths.

Instructions

Validate argument / nested-block paths against the PINNED schema before writing them, e.g. ["bucket", "region", "versioning.enabled"]. Flags unknown, read-only and deprecated paths.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
dirNoTerraform root module directory (must already be initialized). Default: TERRAFORM_CWD_MCP_DIR, else the server's working directory.
kindNoresource | data | ephemeralresource
argumentsYesDotted paths; nested blocks are separated by '.'
type_nameYesFull type name, e.g. aws_s3_bucket

Schema Changelog

Changes observed during successful MCP inspections.

  1. First observedv0.1.0

TDQS

A4.2/5.0
Behavior4/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnly/no-destructive/idempotent/closed-world, so the safety profile is covered. The description adds real behavioral value beyond that: validation happens against the PINNED schema, and the tool flags unknown, read-only and deprecated paths. It does not describe error handling or prerequisites, but the added disclosure is substantial.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loaded with the verb and purpose, followed by one illustrating example and a short second sentence on detected conditions. No filler; every clause carries information.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description usefully indicates what comes back (flags for unknown/read-only/deprecated paths) and when to invoke it. It leaves "PINNED schema" and result shape (list vs error) partly undefined, but remains usable for a 4-param, fully-documented read-only tool.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so all four parameters (dir, kind, arguments, type_name) are already documented in the schema. The description's example path mainly restates the schema's "dotted paths; nested blocks separated by '.'" convention, adding only marginal meaning.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb (validate) on a specific resource (argument / nested-block paths) and gives a concrete example path, so the tool's role is unambiguous. It is clearly distinct from siblings like tf_get_schema or tf_search_types, which retrieve rather than check paths.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

"before writing them" gives an explicit timing/context for when to call this tool, which is genuinely useful guidance. It stops short of naming alternatives or stating when-not to use it (e.g. vs tf_get_schema for a full schema dump).

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.