estimate_terraform_cost

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

With no annotations, the description discloses that the tool is read-only ('BEFORE applying it'), returns a cost delta breakdown, uses AWS on-demand us-east-1 pricing, and lists supported services. It does not mention authentication or rate limits but adequately covers the behavioral traits for estimation.

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 concise with only 8 sentences. It front-loads the main purpose, then describes inputs, output, and supported services in a logical order, with no wasted words.

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?

While the description explains output format and supported services, it omits prerequisites like Terraform installation or AWS credentials, and does not detail how tf_dir execution works (e.g., whether it runs terraform plan itself). However, for a cost estimation tool, it covers the essential aspects well, earning a 4.

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?

Since schema description coverage is 0%, the description fully compensates by clearly explaining each parameter's purpose: plan_json as raw JSON from terraform show, plan_file as file path, and tf_dir to run terraform plan automatically. This adds substantial meaning beyond the schema's type-only definitions.

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?

The description clearly states the tool estimates monthly AWS cost change from a Terraform plan before applying, with specific verb 'estimate' and resource 'cost change'. It distinguishes from sibling tools like estimate_change_cost and estimate_helm_diff_cost by specifying the Terraform context.

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 explicitly lists three input options (plan_json, plan_file, tf_dir) with brief explanations, implying usage when a Terraform plan is available. However, it does not explicitly state when not to use or provide direct comparisons to siblings, leaving some inference needed.

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