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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world). The description adds one piece of behavioral context beyond them - that some cases are 'compulsory' regardless of turnover - but does not say which conditions trigger that (e.g. e-commerce selling or inter-state goods supply), leaving the agent to guess the mechanism.

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?

A single front-loaded sentence with no filler; the decision to be made is stated first and the factors follow. It is slightly dense, since 'compulsory cases' is left undefined, but nothing is wasted.

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?

An output schema exists, so return values need no explanation, and the read-only nature is fully covered by annotations. The remaining gap is minor: the two optional boolean parameters that likely drive compulsory registration are not explained anywhere in the definition.

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 only 40%: state and turnover are documented in-schema, while supplies' enum values, ecommerceSeller and interStateGoods have no descriptions. The description gestures at turnover and 'what it sells' and hints at compulsory cases, but never maps the two boolean flags to the compulsory-registration logic, so meaning is partially - not fully - compensated.

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 (check) and a specific decision (whether GST registration is mandatory for a business in an Indian state), plus the factors considered: turnover, category of supplies, and compulsory cases. This is clearly distinguishable from siblings like calculate_gst or compare_tax_regimes, though it never names those alternatives explicitly.

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 implies the use case (determining registration obligation before registering) but gives no explicit when-to-use/when-not guidance and no routing to siblings such as calculate_gst for actual tax computation. Usage is inferable rather than stated.

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