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

With no annotations provided, the description carries the burden of behavioral disclosure. It states the tool computes and returns values, implying read-only behavior, but does not explicitly confirm no side effects, destructive actions, or other traits. The description is adequate but not rich in behavioral context.

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 three sentences long, each serving a distinct purpose: stating the function, providing usage context, listing inputs and outputs, and directing to related tools. There is no fluff, and it is efficiently front-loaded.

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 description adequately covers the tool's purpose, inputs, and outputs. It does not detail edge cases (e.g., what if price_per_unit equals or is less than variable_cost_per_unit), but given the presence of an output schema and the tool's straightforward nature, the description is sufficiently complete.

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?

The input schema has 100% coverage with clear descriptions for each parameter. The description lists the inputs ('fixed costs, price/unit, variable cost/unit') but adds no additional meaning beyond what the schema already provides, meeting the baseline for full coverage.

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 starts with 'Compute break-even point in units and revenue,' which specifies the verb and the resource. It also distinguishes from sibling tools by mentioning related 'finance-universal' calculators, making its exact purpose unambiguous.

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 provides a usage context ('Use for business plans and pricing decisions') but does not explicitly state when not to use this tool or contrast it with specific alternatives like calculate_profit_margin. The reference to list_bundles is helpful but lacks direct exclusion.

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