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

No annotations are provided, so the description carries the full burden of behavioral disclosure. The description only lists tax types and provinces, but does not explain how the calculation works, what the output represents, whether direction affects results, or any rounding/tax-inclusion behavior. It implies a simple calculation with no side effects, but does not confirm or clarify key behavioral aspects.

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 extremely concise, consisting of a single noun phrase with no filler words. However, it is structurally incomplete: it is not a full sentence and lacks any breakdown of functionality. While every word earns its place, the description is under-specified, so it earns a middle score for conciseness rather than higher for thoroughness.

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?

The tool has 3 parameters, no output schema, and no annotations, so the description must be relatively comprehensive. The one-line description is insufficient to allow correct invocation: it does not explain how the 'direction' parameter alters the calculation, how tax rates differ by province, or what the return format looks like. This is a significant gap for an agent attempting to use the tool properly.

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 only 33% (only 'amount' has a description). The tool description adds no parameter meaning—it does not explain the province codes, the 'direction' enum (add vs extract), or how the amount is interpreted. This is a critical gap because the schema leaves most parameters underspecified, and the description fails to compensate.

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 'GST, HST, PST, and QST for all provinces' clearly identifies the tool as a Canadian sales tax calculator, covering key tax types and all provinces. It distinguishes itself from sibling calculators like us-sales-tax-calculator and eu-vat-calculator by explicitly naming Canadian tax components. However, it lacks an explicit verb like 'calculates', making it slightly less direct than ideal.

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 provides no guidance on when to use this tool versus alternatives, such as US or EU sales tax calculators. It does not state that this tool is for Canadian transactions only, nor does it mention any exclusions or prerequisites. The sibling tool list is provided, but the description itself offers no comparative context.

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