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

Annotations already declare readOnlyHint=true. The description adds that the tool accounts for tax credits lost with the flat tax (children, spouse) and that it recommends the cheaper regime, providing useful behavioral context beyond the read-only flag. It does not disclose all assumptions, but it gives meaningful insight into the calculation logic.

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 informative sentence, front-loaded with the action verb, and includes relevant details without redundancy. It is concise but not overly terse, making it effective and easy to parse.

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?

With 8 parameters, a nested object, and no output schema, the description does not fully specify the return structure or explain all inputs. It does mention the recommendation output, but it leaves out how deductions and the flat-rate percentage factor into the comparison, so an agent may not know what to expect or how to populate all parameters.

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 38%, and the description only partially compensates by mentioning 'yearly income' and 'children, spouse' as factors. It provides no meaning for deduction fields, flatRatePercent, rentalAnnualIncome, or the nested deductions object, leaving the agent to rely on parameter names alone. This is insufficient for a tool with 8 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 uses a specific verb 'Compares' and clearly identifies the two regimes (standard OSVČ vs paušální daň), along with the key factor of lost tax credits and the recommendation output. This distinguishes it from siblings like calc_flat_tax_settlement and check_flat_tax_eligibility, which handle singular calculations or eligibility checks.

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 the primary use case: comparing regimes for a yearly income, and notes the inclusion of tax credits. However, it does not explicitly state when not to use this tool or name alternatives, though the context is clear enough for an agent to select it over more specific calculation or eligibility tools.

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