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

The annotations already declare readOnlyHint=true, so the safety profile is known. However, the description adds confusion by mentioning 'current monthly payment' and 'next income threshold' without clarifying whether these are inputs, outputs, or internal calculations. This creates ambiguity about the tool's behavior beyond what annotations cover.

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 long, run-on sentence with extraneous details. It is not front-loaded and contains unnecessary clauses that could be omitted. A clearer, shorter sentence such as 'Returns the flat tax band (1/2/3) for a given annual income and expense flat rate' would be more effective.

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?

There is no output schema, so the description must clarify the return value. It states the tool determines the band, but also mentions 'current monthly payment' and 'next income threshold', leaving uncertainty about whether these are returned. Given the domain's complexity, the description is incomplete and does not fully explain the tool's role relative to sibling tools.

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 50%: flatRatePercent has a description, annualIncome does not. The description refers to 'annual income' and 'expense flat-rate', providing some meaning for both parameters. But it also introduces non-schema concepts, which detracts from clarity. It partially compensates for the missing parameter description.

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 it determines the paušální daň band for an annual income, using a specific verb and resource. However, it includes extra clauses about 'current monthly payment' and 'next income threshold' that are not in the schema, slightly muddying the purpose but still understandable.

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 tool is for mapping income to a band, which is a common use case, but it does not explicitly state when to use it versus alternatives like check_flat_tax_eligibility or compare_regimes. No exclusions or alternative guidance are provided.

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