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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered. The description adds that the calculation is performed 'por código, com fundamento e premissas', hinting at deterministic, citation-backed output, but it does not describe what the result contains or how the correction/interest are derived from the two dates. Modest added value on top of annotations.

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?

Two compact sentences with the core definition front-loaded and no padding. The second sentence ('A conta é feita por código, com fundamento e premissas') is a bit vague and could have carried concrete parameter guidance instead.

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, all-required financial calculation tool with no output schema, so the description bears responsibility for explaining what comes back (e.g. corrected principal, interest, doubled totals). It says nothing about the result shape or how referenceDate drives correction, leaving a real gap for an agent that must report results to a user.

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 only 50%: the 'refund' enum and 'citationDate' are documented in the schema, while 'charges' and 'referenceDate' are not. The description restates the simple/double distinction already in the enum and alludes to 'correção e juros', but never explains referenceDate (the correction index date) or the charges array structure. It does not compensate for the uncovered half of the parameters.

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 names a specific legal computation – 'repetição de indébito', refund of amounts wrongly charged, simple or double, with correction and interest. That is a clear verb+resource pair an agent can match to a request. It does not explicitly contrast itself with compute-oriented siblings such as debt_calculate or loan_review_calculate, so it stops short of the top score.

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 mention of 'simples ou em dobro' implies the two refund regimes the tool handles, and the schema enum carries the detailed branching rule. However, the description never says when to pick this tool over debt_calculate or loan_review_calculate, nor does it state prerequisites (e.g. that charges must be individually dated). Usage is only implied.

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