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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lower. The description adds genuinely useful behavioral context not in the annotations: results are pre-tax, and the tool cross-checks the raise against inflation. It does not discuss default assumptions for hours_per_week or inflation (those live in the schema), so it stops short of a 5.

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 what is computed, then the input contract, then the sibling routing rules, then a closing scope caveat. Three sentences, every clause carrying distinct information, with no filler or restated title.

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?

Output schema exists, so return values needn't be specified, and annotations carry the safety profile; the description fills the remaining gaps (pre-tax scope, mutually exclusive inputs, unit handling, sibling routing). Nothing an agent needs in order to invoke it correctly is missing.

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 the baseline is 3. The description restates the raise_percent/new_pay mutual exclusivity, but the schema already documents that on both properties ('Give this or raise_percent' / 'Give this or new_pay'), so it adds little beyond the schema except linking pay_unit to the units of both amounts.

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 ('Calculate a pay raise') and enumerates exactly what it returns: new annual/hourly pay, raise per year/month/biweekly, raise percentage, and inflation comparison. It also names the sibling tools it is not (hourly_to_salary, us_paycheck_take_home), so an agent can disambiguate without opening 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?

Gives explicit input-selection rules ('Give either raise_percent ... or new_pay') and explicit exclusions with the alternative named for each: hourly_to_salary for period conversion without a raise, us_paycheck_take_home for after-tax pay. The 'all amounts are before tax' note further scopes when this tool is appropriate.

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