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 reveals nothing about whether this is a read-only calculation, what it returns, or any constraints. The description is essentially empty.

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 extremely short but not in an efficient way; it is under-specified rather than concise. It fails to front-load any useful information about the tool's function.

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 financial calculator with four parameters and no annotations or output schema, the description is entirely inadequate. It does not explain what the tool computes, what the parameters mean in context, or what the result represents.

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. However, the description adds zero meaning beyond the schema. Baseline is 3 when schema coverage is high and description provides no extra parameter info.

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 "Simple Interest: Simple Interest" is a tautology that merely restates the tool name. It does not state a clear verb or what operation is performed (compute? convert?). An agent cannot distinguish this from sibling x402-compound-interest based solely on the description.

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 is provided on when to use this tool versus x402-compound-interest or other finance tools. The description offers no context, prerequisites, or exclusions.

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