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

With no annotations, the description carries the full burden and discloses key assumptions: 2026 tax bands, projected SI rate increases in 2029/2034/2039, dependants handling, and anti-inference of contribution history. It does not state determinism, error behavior, or side effects (though a calculator is implicitly pure), leaving minor gaps.

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?

Front-loaded with purpose and usage, but the first sentence and the second sentence redundantly restate what the tool estimates. The guidance is otherwise dense and earns its place, but trimming the duplication would improve conciseness.

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?

Given 7 parameters, conditional requirements, no annotations, and an existing output schema, the description covers modes, required inputs, assumptions, and anti-inference rules well. It does not elaborate on edge cases like out-of-range retirementAge or on the exact nature of the returned result, though the output schema handles the latter.

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 baseline is 3. The description adds cross-parameter semantics beyond the schema: mode and retirementAge are always required; quick mode needs currentAge, yearsWorked, totalInsuranceUnits; advanced mode needs yearlyUnits. It also reinforces that yearsWorked/totalInsuranceUnits must not be inferred and that legacy unit maps are accepted.

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 (estimates), resource (Cyprus state contributory pension amount at retirement), and the exact basis (insurance units, contribution history, 2026 tax bands). This clearly distinguishes it from siblings like get_pension_reference_data, parse_pension_statement, and run_retirement_stress_test.

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 when to use it ('Use to estimate contributory Cyprus state pension entitlement'), and provides detailed conditional guidance for quick vs advanced mode, required fields per mode, and the dependants assumption. It also instructs never to infer contribution history and to ask only for missing essentials.

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