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

No annotations are provided, so the description must disclose behavioral details. It only states the tool compares net yield but does not explain how net yield is calculated, what data sources are used (e.g., current rates), whether taxes/fees are included, or any limitations. The 'net' qualifier implies some treatment of costs but is not elaborated.

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, efficient sentence that front-loads the core action ('Compares net yield...') and immediately specifies the key constraint ('same value and term'). There is no extraneous content; every word contributes to the purpose.

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 tool that compares 'different investments', the description does not indicate what types of investments are considered, whether real-time data is used, what the output format is (no output schema provided), or any prerequisites. An agent would struggle to predict the tool's behavior or results, making it incomplete for confident invocation.

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?

The input schema fully documents both parameters (principal and months) with clear descriptions. The tool description adds the context that both parameters apply to 'the same value and term' (mesmo valor e prazo), which reinforces their purpose but adds no syntactic or semantic detail beyond the schema. With 100% schema coverage, a baseline of 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 action ('compares net yield'), a resource ('different investments'), and a clear context ('side by side for the same value and term'). It is distinct from generic 'calculate' tools but does not explicitly differentiate from siblings like compare_pgbl_vgbl or compare_with_cdb, so it misses full sibling separation.

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?

There is no guidance on when to use this tool versus the many sibling comparison tools (e.g., compare_loans, compare_pgbl_vgbl, compare_with_cdb). No alternatives or exclusions are mentioned, leaving the agent to infer usage solely from the name and description.

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