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

No annotations are provided, so the description carries the full burden. It discloses the payment requirement ($0.25 USDC on Base) and describes the output structure (per-module costs, whole-project costs under each candidate model). This is significant behavioral context beyond the schema, though it does not mention any side effects like data modification or rate limits.

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?

Two sentences with zero filler. The core purpose is front-loaded, and the parameter constraint and payment note are integrated efficiently. Every part of the description earns its place.

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?

The tool is moderate in complexity (2 parameters, one required). The description covers usage, parameter values, payment, and output summary. Since an output schema exists, detailed return value documentation is not necessary. The description is complete for an agent to invoke it correctly.

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 0%, so the description must explain both parameters. It does: project_description is the input to be broken into modules, and architecture_template is enumerated with valid values and a clear auto-suggest behavior. This fully compensates for the lack of schema descriptors.

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 uses a specific verb ('Break') and resource ('software project description') and states the output precisely: per-module cost estimates, the cheapest model per module, and whole-project comparisons. This is unambiguous and distinct even without sibling tools defined.

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 gives explicit guidance on the architecture_template parameter (must be one of five values or left blank for auto-suggest) and mentions the required payment. Since there are no sibling tools to differentiate from, the guidance is sufficient for correct usage, though it does not explicitly state when NOT to use the tool.

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