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

With readOnlyHint already present, the description adds valuable context: 'All figures come from the deterministic Freelax engine, never from the model.' This tells the agent the output is reliable and not AI-generated, which is important for a computation tool. It also specifies the scope of computation, going beyond the annotation without contradicting it.

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 two sentences, front-loaded with the primary action, and every phrase carries meaning. It efficiently lists the computed outputs and the deterministic-engine guarantee without unnecessary detail.

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 with 23 parameters, nested objects, no required fields, and no output schema, this description is incomplete. It explains what is computed but not the response structure, default behaviors, validation rules, or how results are presented. Since output schema is absent, more detail is needed for an agent to use it effectively.

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 26%, and the description does not compensate. While it mentions parameter groups (children, spouse, deductions), it fails to explain individual parameters like hasZTP, isStudying, citizenshipType, or the precedence of annualBusinessIncome over monthlyBusinessIncome. The description adds little beyond what the sparse schema already states.

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 clearly states the tool's function: 'Computes a full Czech OSVČ tax year from personal facts' and lists specific components (income tax, insurance, set-aside, safe-to-spend, flat-tax band, regime eligibility). This distinguishes it from sibling tools that handle more specific calculations (e.g., calc_flat_tax_settlement, compare_regimes) by emphasizing the full-year scope.

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 provides clear context: 'full Czech OSVČ tax year' and enumerates what the computation covers, implying use when a comprehensive annual calculation is needed. However, it does not explicitly mention when not to use this tool or name alternative tools, so it falls short of a 5.

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