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

Annotations already establish that this is a read-only, idempotent, non-destructive calculator. Beyond that, the description usefully enumerates what the calculation covers, including interest accrual, cap-vs-discount conversion pricing, shares, and effective discount. It does not describe rounding, error behavior, or output structure in detail, but it adds meaningful behavioral context for a calculator.

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 short and front-loaded, starting with the core calculation and output dimensions. The SAFE alternative and interactive URL are placed after the essential purpose, and there is no wasted wording.

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 an eight-parameter calculator with fully described inputs and read-only annotations, the definition is complete enough to invoke correctly. It also compensates for the absence of an output schema by naming the key computed outputs: accrued interest, conversion price, shares received, and effective discount.

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 input schema already explains the parameters, including principal, round price per share, cap, discount, years, interest rate, and interest mode. The description does not add parameter-specific syntax or constraints beyond the schema, so the baseline 3 is appropriate.

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 states a specific financial calculation: how a convertible note converts in a priced round, including accrued interest, conversion price, shares received, and effective discount. It also explicitly distinguishes this tool from the SAFE conversion sibling, so an agent can identify the resource and scope without inspecting the schema.

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?

It directly says to use safe_conversion for SAFEs because they have no interest, which is an explicit alternative and condition. For the convertible-note case, the purpose sentence itself supplies the context for when this calculator applies.

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