get_gst_category_codes_sg

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

With no annotations, the description carries the behavioral disclosure burden. It discloses the source IRAS e-Tax Guide, explicitly scopes the code list, and explains that `rate` is null for categories with no fixed rate, which adds real behavioral detail beyond the tool name.

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 three sentences with each sentence earning its place: the first states the core purpose, the second provides source and scope, and the third clarifies null behavior. It is front-loaded and compact with no fluff.

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 zero-parameter lookup with no annotations and an existing output schema, the description fully covers necessary context: source, scope, and a key return-value edge case. Nothing critical is missing for an agent to invoke this 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?

The tool has zero parameters and the input schema is empty, so the schema coverage is effectively complete. The description correctly adds no unnecessary parameter information, meeting the baseline for a parameterless tool.

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 a specific action ('Return') and resource ('IRAS GST category codes accepted on Singapore invoices'), making the tool's purpose unambiguous. It also distinguishes this from sibling codelist tools by specifying the exact tax category codes and the Singapore invoice context.

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 gives clear context for use by stating the source is the supply/output-tax side only and explicitly excludes purchase-side codes for sent invoices. It does not name an alternative tool for purchase-side codes, but the exclusion still provides useful guidance.

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