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

Annotations only declare readOnlyHint and openWorldHint=false, so the credit here goes to the description's substantive additions: the 2026/2027 Maternity Benefit rates (€299/€309 weekly) and the tax treatment (taxed but exempt from USC and PRSI). These materially affect the computed result and are not available in the schema or annotations, though assumptions about top-up taxation and model limits are not stated.

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?

It is a single dense sentence with the jurisdiction and subject front-loaded, followed by outputs and then rate details in a parenthetical. Nothing is redundant, though the rate figures crammed into the parenthetical make it slightly harder to parse at a glance.

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?

With 8 parameters, no output schema, and only read-only annotations, the description usefully compensates by spelling out the three return components (per-parent take-home, household gap, monthly saving target). It is nearly complete for an agent to call it, missing only default behavior for the optional weeks/salary fields.

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 100%, so every parameter including the year enum, top-up weeks, and parent's benefit flags is already documented. The description adds only indirect context (that both parents are modeled and that the year drives the benefit rate), so the baseline of 3 applies.

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 names a specific domain (Ireland maternity/paternity/parent's leave pay) and enumerates the concrete outputs: each parent's take-home pay versus a normal year, the household gap, and a monthly saving target. The verb is implicit (it computes/compares) rather than stated, and it never distinguishes itself from the very similar sibling parental_leave_income_gap.

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?

There is no guidance on when to use this versus alternatives, despite a nearly identical-looking sibling (parental_leave_income_gap) and other income tools (ireland_budget_2027_take_home, ireland_what_can_i_claim). No prerequisites or exclusions are stated; the agent must infer the use case entirely from the topical phrasing.

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