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

With no annotations provided, the description carries full burden. It notes the tool is deterministic and returns specific fields. It does not disclose potential side effects, error handling, or authorization needs, leaving some behavioral traits unaddressed.

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?

The description is four sentences long, front-loaded with purpose, and avoids redundancy. Every sentence adds value: purpose, warning, and expected output. 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?

Given 4 parameters and no output schema, the description covers the main computation steps (tables, subsidy) and lists output fields. However, it omits explanation of the paid_in_january parameter and error conditions, leaving minor gaps for an agent.

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 baseline is 3. The description adds minimal parameter context beyond listing period options ('monthly or annual') and mentioning return values. It does not explain the paid_in_january parameter or elaborate on year defaults.

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 clearly specifies the tool computes Mexican ISR withholding using official SAT tables, with a specific verb ('Compute') and resource ('Mexican ISR withholding'). It distinguishes from siblings (calc_aguinaldo, calc_finiquito, calc_imss) by focusing on income tax specifically, leaving other payroll calculations to 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?

The description states when to use ('Compute Mexican ISR withholding') and includes a strong directive not to estimate from memory, implying this tool is authoritative. However, it does not explicitly mention when not to use or name sibling alternatives as alternatives.

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