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

With no annotations provided, the description carries the full behavioral burden. It openly discloses that the tool never processes payment, which is the most important behavioral trait. It also reveals conditional behavior: passing api_key returns balance, shortfall, and USD conversion, and lang controls output language. It does not discuss response format or credential handling, but for an informational tool this is solid coverage.

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 front-loaded with the core purpose and safety boundary, then gives language and conditional-parameter guidance in a compact form. The bilingual repetition slightly lengthens it, but every sentence contributes operational value for the intended audience.

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 no output schema, three optional parameters, and eighteen siblings, the description covers the purpose, scoping, key behavioral constraints, and parameter-triggered behavior. It could add explicit alternatives or a note that api_key is sensitive, but nothing essential is missing for an agent to select and call 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?

Schema coverage is 100%, so the baseline is 3, but the description adds meaningful behavior for all three parameters: lang="en" selects the English guide, amount is used to compute shortfall, and api_key triggers balance and USD-conversion enrichment. This goes beyond the schema's plain descriptions and helps an agent decide how to fill the parameters.

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 action and resource: 'Explain how to add funds (deposit) to a hotlikeshop account.' It also clearly distinguishes itself from transaction tools by stating 'MCP never processes payment,' which separates it from siblings like buy_product. The bilingual wording reinforces intent without ambiguity.

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 usage context: it is informational only, covers USDT payment options for international users, and explains when to pass lang, amount, and api_key. It does not explicitly name sibling alternatives or state 'use this instead of buy_product,' but the 'Info only — MCP never processes payment' boundary communicates 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.