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

Annotations already establish readOnly/idempotent/non-destructive/closed-world, so the safety profile is covered. The description adds meaningful context beyond that: computations follow Försäkringskassan's official rules and results are delivered "med källa" (with a source citation), which tells the agent the output is rule-derived and attributable. It stops short of describing response shape or handling of missing inputs.

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 dense sentence that front-loads the verb and resource before listing outputs; every clause contributes a distinct computed result. It is slightly run-on and could be broken up, but there is no filler.

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 no output schema, the description usefully enumerates what will be returned (balances by level, reserved days, double days, age-4 deadline with the 96-day cap, 12-year cutoff) and notes the regulatory basis. Only minor gaps remain, such as default handling for the optional idag and confirmatory output format.

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 each of the four parameters (fodelsedatum, idag, foraldrar, uttagna_dubbeldagar) is already documented in the schema. The description adds no parameter-level detail — e.g. it never clarifies that uttagna_dubbeldagar counts days per parent or how the optional idag defaults — so baseline 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?

States a specific verb ("Räkna ut" / calculate) and resource (remaining parental days per parent), then enumerates the exact outputs: sjukpenningnivå, lägstanivå, reserved days, double days before 15 months, days required before age 4, and final withdrawal date at 12 years. That output profile clearly separates it from calc_benefit (money), plan_leave (scheduling), and the rules/explanation siblings.

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 only implied: an agent can infer this is the tool for computing remaining day balances, but the description never says when to choose it over calc_benefit or plan_leave, nor states prerequisites (e.g. that taken-days inputs must be supplied per parent).

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