calculate_investment_return

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

With no annotations, the description carries the full burden of behavioral disclosure. It does disclose the core behavior: simulating fixed-income yield, calculating regressive income tax, and comparing with savings. However, it does not clarify key assumptions such as whether returns are gross or net, whether contributions are made over time, or how the comparison is presented.

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 a single dense sentence that front-loads the main purpose and packs in useful specifics about tax and savings comparison. It is appropriately short, though it tries to cover several instruments in a compact list and includes the problematic LCA mention.

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?

This is a four-parameter simulation tool with no output schema and no annotations, so the description must do more. It does not describe the return value format, explain whether the calculated return is net of tax, or reconcile the missing LCA enum value. An agent would be guessing about important aspects of the call and result.

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%, so the baseline is 3. But the description explicitly lists 'LCA' as a supported instrument while the schema enum only allows cdb, lci, tesouro_selic, and poupanca. This can mislead an agent into sending an invalid type value, which is a meaningful semantic inconsistency beyond what the schema describes.

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 verb and resource: it simulates fixed-income returns in Brazil and names the covered instruments (CDB, LCI, Tesouro Selic, Poupança). It also distinguishes itself from generic siblings like calculate_compound_interest by mentioning Brazilian-specific tax treatment (IR regressivo) and comparison with savings.

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?

The description implies when to use the tool: when modeling Brazilian fixed-income investments and comparing them to savings. However, it does not explicitly state when not to use it or name alternatives such as calculate_compound_interest or get_current_rates, so the guidance is left mostly to inference.

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