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

No annotations are present, so the description carries the burden. It explicitly discloses that the tool is read-only)SkipTransformers, no api_key required, and that it lists which other tools need an api_key. This is useful and honest. It does not describe the output format, but for an onboarding guide this is a minor gap.

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 well structured with explicit WHEN TO USE and PREFER INSTEAD sections.text is compact, front-loads the purpose, and the bilingual content is intentional and self-documenting.

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 read-only guide with one optional language parameterabweeks, the description covers when to use it, what it covers, auth/key requirements, read-only behavior, and alternatives. No output schema exists but the function is simple enough that the description is sufficient.

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 schema has one optional lang parameter with full coverage (100%). The description adds that 'en' is the default and gives a bilingual explanation, which reinforces the semantic without needing extra detail.

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 verb+resource ('Onboarding guide... how to start buying'), lays out the exact workflow (create account -> get api_key -> top up -> search & buy), and distinguishes itself from siblings by naming what it is not (topup_guide, quote_order, buy_product, search_products). An agent can tell exactly what this tool is for.

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?

Explicit 'WHEN TO USE' states it is the very first call for a new/international user or whenever someone asks 'how does this work'. It also gives 'PREFER INSTEAD' alternatives for top-up details, purchasing, and browsing, leaving no ambiguity about when not to use it.

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