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

With no annotations, the description carries the full burden of behavioral disclosure. It reveals the three calculations performed, which is the core behavior. However, it does not disclose the return format, assumptions, edge cases, or that it is a pure computation with no side effects. This is adequate but not rich.

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 a single, information-dense sentence that front-loads the tool name and immediately states the purpose and key outputs. There is no filler or redundant information, making it highly efficient.

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 calculator with five required inputs and no output schema, the description identifies the main outputs but leaves gaps: it does not explain how inputs map to outputs, what the results look like, or any constraints or assumptions. It provides a sufficient overview but lacks interpretive guidance for a moderately complex financial tool.

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%, and the description does not explicitly list or define any of the five input parameters. It makes indirect conceptual references (e.g., 'customer goal' implies newCustomersGoal and leadToCustomerRate), but it does not clarify specifics like targetLtvCacRatio or blendedCostPerLead. This is insufficient to understand all inputs correctly.

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's function: 'Work out your lead generation budget' and specifies three concrete outputs (leads needed, implied CAC vs LTV target, maximum cost per lead). This distinguishes it from sibling calculators like cac_ltv_calculator, which focus on the ratio rather than the full budget planning.

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 the primary use case by tying it to lead generation budgeting, but it does not explicitly state when to choose this tool over alternatives such as cac_ltv_calculator or roas_calculator. No exclusionary or comparative guidance is provided, only a general scenario.

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