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

No annotations, so the description carries the full burden, and it does well: it discloses that this is an estimate bounded by the payslip, the tax regimes applied (PP 58/2023 TER vs December annual recalculation), and that output is itemized per line with its decree. It does not discuss determinism, precision, or rounding, which leaves a modest gap for a no-annotation tool.

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?

Three compact sentences, purpose front-loaded, then input mode, then the caveat. No redundancy and every clause carries information (deduction types, decree basis, UMK option).

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 9-parameter calculation tool with no output schema, the description correctly conveys what is computed and hints at the itemized return ('each line with its decree'). It is close to complete; only the exact return shape and which statutory constants are assumed by default are left implicit.

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 already 100%, so the baseline is 3, but the description adds real value: it clarifies the mutual exclusivity of gross and regency_code (the latter substituting the kabupaten/kota UMK as gross) and explains that the month parameter selects the TER table versus December recalculation. These clarify intent beyond the field-level docs.

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 (calculate), resource (net/take-home pay), and precise scope: worker BPJS deductions (JHT, JP, JKN), PPh 21 via PP 58/2023 TER or December recalculation, plus employer contributions. This cleanly distinguishes it from the data-lookup siblings (get_bpjs_rates, get_pph21_ter, get_ptkp), which fetch rates rather than compose them into a salary computation.

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 input-mode context ('Give gross, or regency_code to use that kabupaten/kota UMK') and a caveat ('An estimate; the employer payslip decides'), but never states when to pick this tool over the sibling getters, nor any when-not condition. Usage is implied rather than explicit.

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