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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=false and destructiveHint=false, so the safety profile is covered. The line 'A conta é feita por código, com fundamento e premissas' hints that the result carries legal grounding and stated assumptions, but it does not say what the output contains, what assumptions are applied, or how nulls are treated beyond the one schema note.

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 that front-load the legal basis and purpose; little waste. The phrase 'A conta é feita por código' is slightly opaque but does signal a deterministic implementation.

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 legally-grounded calculator with six required inputs, no output schema and near-empty parameter documentation, the description leaves too much unstated: what the result looks like (ratio, plan proposal, fundamento), which assumptions are applied, and when null values fall back to decree defaults for fields other than existentialMinimum.

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 only 17% — only existentialMinimum is documented (null uses the decree value). The description does not explain debits, netIncome, essentialExpenses, planCapacity or date formats, so it fails to compensate for the coverage gap on a 6-required-parameter tool.

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 calculation tied to a statute (Lei 14.181/2021): the ratio of consumer debts to income for a payment plan. That is a clear verb+resource and is more specific than a generic debt calculator, though it never explicitly distinguishes itself from siblings like debt_calculate or undue_charges_calculate.

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?

'Para o plano de pagamento' implies the context of use (structuring a consumer insolvency payment plan), but there is no explicit when-to-use or when-not guidance and no mention of alternatives among the many sibling calculators. Usage has to be inferred from the legal framing.

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