estimate_change_cost

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

No annotations provided, so description must disclose behavior. It states read-only, never applies anything, and explains verdict types and behavior when no budget ('no_budget' verdict, cost delta still returned). Does not mention error handling or rate limits, but sufficient for a read-only tool.

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?

Well-structured with bullet points and sections. First paragraph states purpose and outputs, second declares read-only, third describes input methods, fourth covers budget_name, fifth lists triggers. No wasted sentences; each adds value.

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?

Given 6 optional parameters, no annotations, and no output schema, the description fully covers input options, behavior, verdicts, and triggers. Provides enough for an agent to decide when and how to invoke this tool over siblings like estimate_terraform_cost.

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 coverage 0%, but description explains all 6 parameters in detail: terraform plan variants, helm_diff, monthly_delta_usd with example, budget_name with default behavior. Adds meaning beyond schema (e.g., 'escape hatch for any change the estimators don't parse').

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?

Clear verb+resource: 'Cost preflight for a proposed change' and lists exact verdicts (ok, warn, over_budget, no_budget). Distinguishes from siblings like estimate_terraform_cost by being a combined cost+budget check and stating 'Agent-native. Call this BEFORE applying'.

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?

Explicit triggers listed ('will this fit my budget', 'cost preflight') and instruction to call before applying. Could be improved by specifying when not to use (e.g., for already-applied changes use explain_cost_change), but still gives clear context.

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