calc_compound_interest

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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds no further behavior – it doesn't say what formula convention is used, what defaults apply when optional inputs are omitted, or what is returned. With annotation coverage the bar is lower, but for a numeric tool the unstated defaults matter.

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?

A single front-loaded sentence with no waste, but its brevity reflects under-specification rather than economy of language. There is room for one clarifying clause without bloat.

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 5-parameter numeric tool with 0% schema coverage and no output schema, the description should cover defaults, compounding convention and the shape of the result. None of that is present, so an agent cannot call it confidently for non-trivial cases.

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 compensate and it does not mention any parameter. Three required names (principal, annual_rate, years) are self-explanatory, but compounds_per_year and monthly_contribution have no stated defaults or contribution-timing semantics, leaving real ambiguity.

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+resource ('Calculate compound interest growth'), so an agent knows exactly what domain it handles. It does not distinguish itself from near-neighbours like exponential_growth or calc_mortgage, so it stops short of a 5.

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?

No guidance on when to prefer this over sibling calculators (e.g. exponential_growth, calc_mortgage) and no stated preconditions or exclusions. The reader must infer usage entirely from the name.

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