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

No annotations are supplied, so the description carries the full burden, and a pure read-only math tool has a low risk profile, so little is needed. It does add genuinely useful behavioral context by disclosing cost and payment rail ($0.002/call, USDC, eip155:8453), but says nothing about output shape, precision or rounding behavior.

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?

Single front-loaded sentence that states the outcome first, with the pricing note clearly segregated after an em dash. Efficient, though the price clause is slightly disruptive to the sentence flow.

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 four-parameter deterministic calculator with no output schema, the description covers the inputs and hints at the return values ('future value' and 'total interest earned'). Nothing critical is missing, though a note on output fields would fully close the loop.

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 100%, so the schema already documents all four parameters, setting the baseline at 3. The description restates the compounding choice mapped to the timesPerYear enum but adds no units, ranges, or interpretation guidance beyond the schema.

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?

States a specific verb and resource ('Project the future value of a deposit with compound interest') and enumerates the compounding options, which cleanly separates it from sibling calculators like loan_payment, CAGR and ROI.

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?

There is no guidance on when to pick this over finance_cagr_calculator or calculators_loan_payment_calculator, and no prerequisites or exclusions stated. The enumeration of compounding periods is parameter information, not usage guidance.

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