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

Annotations already establish readOnlyHint/idempotent and no side effects, so the bar for safety disclosure is low. The description adds substantive domain behavior beyond the annotations: the year-based percentage schedule, the categories of hours excluded from the denominator, the daily-ratio constraint on apprentice hours, and the $50/$500 cure rates.

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 front-loaded with the core purpose and every clause is regulation-relevant rather than filler. The single dense paragraph with stacked parentheticals hurts scanability, but nothing extraneous is present.

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 read-only calculation tool with no output schema, the description covers the rule, the inputs' meaning, and the shape of the return (required hours, shortfall, cure). It stops short of describing result formatting/rounding, but an agent has enough to invoke it correctly.

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 schema already documents all six parameters, including the good-faith-hours and participation-failure semantics. The description restates the underlying rule (exclusions, ratios) but adds no per-parameter syntax or format guidance beyond what the schema carries, making the baseline 3 appropriate.

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 the exact task (the apprenticeship labor-hours requirement for one facility) with a regulatory cite and enumerates what comes back: required hours, shortfall, and the IRS cure. It is unambiguous what the tool computes, though it does not explicitly distinguish itself from the closely related sibling count_participation, which also concerns participation shortfalls.

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 rather than stated: it is clearly a per-facility computation used when testing the 1.45-8(b) requirement. The only routing hint ('Use check_daily_ratio to find them') appears inside a schema property, not the description, and there is no explicit when-to-use versus count_participation or check_good_faith_request.

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