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

Annotations already declare a read-only, idempotent, non-destructive local computation, and the description layers on the substantive caveats: PCB assumes flat salary from January and no TP1 reliefs, results are ESTIMATEs, and the agent should relay warnings. This is exactly the kind of assumption disclosure an agent needs before quoting a figure to a user.

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 the purpose, then the date range, then the estimate caveats and relay instructions — a sensible order. The closing Bahasa Melayu keyword sentence is somewhat redundant with the locale parameter documentation, costing a little tightness.

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 11 parameters and no output schema, the description does the important work of bounding accuracy (estimate, flat-salary PCB assumption) and directing how to present results. It stops short of describing the breakdown structure a caller receives, which would be the remaining item given there is no output schema.

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 every one of the 11 parameters (including zakat, age60, lindung, epf_rate, tax_category) is already documented in the schema. The description restates the date-to-tax-year mapping and the locale effect but adds no syntax or default detail beyond what the schema provides. 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 and resource ('estimates a Malaysian employee's monthly take-home pay from gross salary') and enumerates the exact deductions computed (EPF/KWSP, SOCSO, EIS, LINDUNG 24 Jam, PCB) plus employer contributions. An agent knows precisely what number comes back and on what basis.

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 the operating envelope explicitly: pay dates 2026-06-01 to 2027-12-31, with the date selecting YA2026 or YA2027 rules. It also tells the agent how to relay results (state tax year and date, pass on warnings). No alternatives exist to route against, so the only gap is absence of explicit out-of-scope exclusions.

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