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

Annotations already establish readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds genuine behavioral context beyond that: it discloses the counting model (paid PRSI + up to 520 credits + HomeCaring Periods) and the 2,080-contribution threshold for the full rate, which an agent needs to interpret results. It stops short of stating output format or how drawdown variants change the answer, but with no output schema the 'weekly rate' phrasing still signals the return type.

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?

A single front-loaded sentence with the estimate target stated first and the formula detail parenthetically appended. No filler, no repetition of the tool name, and nothing that could be cut without losing 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 a four-parameter deterministic calculator with full schema coverage and no output schema, the description supplies the domain rules needed to call it sensibly and to interpret the result. The remaining gap is the drawdown parameter's effect on outcomes and any note on partial-rate behavior below thresholds.

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 the baseline is 3, but the description adds meaning beyond the schema by tying paidWeeks, creditWeeks, and homeCaringWeeks to the TCA aggregation and by stating the 520-credit cap and the 2,080 full-rate threshold. It does not explain how the drawdown enum values influence the calculation, which is the one parameter left purely to its schema 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?

Names a specific verb and resource — 'estimate the State Pension (Contributory) weekly rate' — plus the governing methodology (Total Contributions Approach). This clearly distinguishes it from siblings like ireland_myfuturefund_pension and ireland_what_can_i_claim without needing to open any 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?

Usage is implied: an agent should call it when it has PRSI contribution data and wants a weekly pension estimate. There is no explicit when-to-use or when-not-to-use statement, and no routing to alternative calculations (e.g., a means-tested or non-contributory pension sibling).

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