tf_plan

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

With no annotations provided, the description carries full burden. It clearly states the tool is safe and makes no changes, which is the key behavioral trait. It also mentions it returns a human-readable diff, indicating output format. However, it does not disclose error handling, exit codes, or potential failure modes (e.g., state lock issues). The transparency is good but not exhaustive.

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

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

The description is only two sentences, both front-loaded with essential information. Every sentence earns its place: the first explains the action and output, the second emphasizes safety. No unnecessary words or repetition. This is an example of ideal conciseness.

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

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

For a tool with 6 parameters, no output schema, and no annotations, the description provides the core purpose and safety guarantee but lacks operational context. It does not mention that the tool requires an initialized Terraform working directory, that it may use state locks, or how the plan file (savePlanFile) can be used with tf_apply. While adequate for basic understanding, it leaves gaps for an AI agent to infer important steps.

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

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

Schema description coverage is 100%, so all 6 parameters are documented in the schema. The description adds no additional meaning or usage hints beyond what the schema provides (e.g., it doesn't explain that 'vars' accepts multiple key=value strings). Per guidelines, baseline 3 is appropriate when schema covers parameters fully and description adds no extra value.

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

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

Description clearly states the tool runs 'terraform plan' and returns a human-readable diff. It emphasizes safety ('Safe — makes no changes to infrastructure'), which distinguishes it from sibling tools like tf_apply and tf_destroy. The verb and resource are specific and well-understood.

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

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

The description implies usage for previewing changes before applying (by stating 'Safe — makes no changes'), but it does not explicitly state when to use this tool versus alternatives like tf_apply. There is no mention of prerequisites (e.g., initialized workspace) or scenarios where this tool should not be used. While the safety warning is helpful, clearer guidance on workflow sequencing would improve the score.

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