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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It explains the core outputs but omits assumptions (e.g., constant real return), input requirements, or side effects. It adds some context but is not comprehensive.

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, consisting of a single sentence that is easy to parse. The initial 'Purchase Impact Calculator' repeats the title, but the remainder delivers meaningful detail without redundancy.

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 the tool's complexity (7 parameters, no annotations, no output schema), the description is too high-level. It fails to clarify which inputs are required, what optional parameters do, or what the result looks like, leaving the agent to make risky assumptions.

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?

With 0% schema description coverage, the description must compensate by explaining parameters. It only loosely references concepts like price, invested, days of work, and FIRE date without defining how parameters like expectedRealReturnPct, monthlySavings, or fireNumber contribute. This is insufficient for a 7-parameter tool.

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 what the tool does: it computes the true cost of a purchase in terms of investment growth, work days, and FIRE date delay. The verb 'See' and specific outcomes distinguish it from sibling calculators like compound_interest_calculator and fire_calculator.

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 clear use case ('any purchase') and implies when this tool is appropriate. However, it does not explicitly mention alternatives or state when not to use it, so it falls short of full usage guidance.

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