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

With no annotations, the description carries the full behavioral burden and does well: it discloses year-specific rule selection, the 20% CGT rate, CPI indexation, the 0.4% transfer fee, the EUR modelling-convention default, and the non-inference rule for first-disposal eligibility. It stops short of describing error behavior or result shape, but an output schema exists to cover returns.

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?

Dense and front-loaded, with the core purpose in the first clause and defaults and pitfalls after. There is mild redundancy between the opening sentence and 'Use for Cyprus capital-gains tax on an immovable-property sale', which restates the purpose without adding information.

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 an 8-parameter tax calculator with full schema coverage and an output schema, the description supplies everything an agent needs: when to use, defaults, year selection, exemption-claim semantics, and instructions to elicit missing required inputs rather than guess.

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 100%, so 3 is the baseline; the description goes slightly beyond it by flagging which inputs are essential to collect (acquisition price/year, disposal tax year, sale price, property type) and by framing the currency default as a modelling convention rather than a real-world assumption. The remaining parameters (agentFees, isFirstDisposal) are left to the schema's own descriptions.

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?

States a specific verb and resource (calculates Cyprus Capital Gains Tax on an immovable property disposal) and pins the scope to 2025/2026 rules. This is unambiguously distinct from siblings like calculate_cyprus_income_tax, so an agent can select it without opening the schema.

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?

Explicitly says 'Use for Cyprus capital-gains tax on an immovable-property sale' and instructs the agent to ask for missing essentials rather than fabricate values. It also clarifies the default-to-2026 rule and that omission of isFirstDisposal means no exemption is claimed. It does not name an alternative tool to use when the disposal is outside Cyprus, but no sibling is close enough to be a likely confusion.

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