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

There are no annotations, so the description carries the full burden. It explains the conceptual behavior of the calculation (prepayment vs redemption timing) but does not disclose what the output represents, its units, or any assumptions beyond the same-rate CDB. This leaves important behavioral ambiguity.

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 three sentences with no fluff. It front-loads the calculation's purpose, then gives the key condition, then parameter usage. Every sentence earns its place.

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?

The description explains the underlying concept and constraints well, but with no output schema and no annotations, it should clarify what the result means (e.g., cost in R$, percentage, annualized). That missing information is significant for a specialized financial calculator.

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 coverage is 100%, setting a baseline of 3. The description adds value by explicitly labeling required vs optional parameters and insisting on exact English parameter names, which prevents an agent from translating or renaming them. This is practical 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?

The description clearly states the verb 'Calcula' and the specific resource: the cost of come-cotas (semiannual IR prepayment on open funds) compared with a CDB of the same rate. It is specific enough to identify the tool's purpose, though it does not explicitly differentiate it from the sibling compare_with_cdb.

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 provides clear context for when the calculation is valid, including the minimum 25-month term and the condition that only the timing effect remains. It distinguishes required vs optional parameters but does not explicitly state when to prefer this tool over alternatives.

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