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

Beyond the readOnlyHint annotation, the description adds substantial behavioral context: it is READ-ONLY and 'creates nothing, hires nobody and files nothing.' It discloses the calculation source (LHDN's official MTD method, with a written confirmation reference), spells out all default assumptions, mandates repeating assumptions to the user, and positions the result as an estimate rather than a quote or tax advice. This is exemplary transparency.

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 long but every sentence earns its place: use case, parameter semantics, tax computation provenance, default assumptions, compliance guardrails, and access restrictions. It is front-loaded with the core purpose and then moves systematically through parameter details. There is no filler or tautology.

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 there is no output schema, the description clearly states what the tool returns: employer cost and employee take-home. It fully covers the five parameters, the applicable tax method, the default assumptions, and the mandatory communication requirement to repeat assumptions to the user. This is more than enough for an agent to select, invoke, and interpret the tool 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 0%, so the description carries the full burden, and it delivers. It explains monthlyWage through the RM4,000 example, residency via RESIDENT/NON_RESIDENT and the flat 30% tax rate, citizenship via HRD Corp levy and SKBBK effects, ageBand via reduced EPF and SOCSO Category 2, and epfEmployeeRate via the employee's elected reduced EPF rate. Every parameter receives meaning beyond its raw schema definition.

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 opens with a specific verb and resource: 'Cost a HYPOTHETICAL hire' and concretely defines the outputs: employer cost (wage plus EPF, SOCSO, EIS, HRD Corp levy) and employee take-home pay. It gives a representative question ('if I hire someone at RM4,000...') that makes the tool's scope unmistakable and distinguishes it from generic payroll or reporting 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?

It gives explicit when-to-use framing with example questions and explains the default assumptions users should expect. It also provides role restrictions ('ADMIN AND BOOKKEEPER + PAYROLL ONLY'). However, it does not name any alternative sibling tool or explicitly state when NOT to use this tool, so the guidance stops short of a full when-versus-alternatives treatment.

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