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

With no annotations provided, the description alone must disclose behavior. It reveals one behavioral trait (empty protocol returns top-20 list) but omits return format, error handling, case sensitivity, or whether the protocol name must be exact. For a read-only tool this is minimal but functional.

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?

Two brief sentences with no redundancy. The first states the core purpose, and the second provides a key usage hint. Extremely concise and front-loaded.

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 simple one-parameter tool with no output schema, the description covers the main use case but leaves gaps around return value shape and potential edge cases. It is sufficient for basic invocation but not fully self-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 provides no description for the 'protocol' property, and the description adds a specific behavioral note: leaving it empty yields a top-20 list. This gives partial meaning, but it does not explain what values are valid (e.g., exact names, slugs, case) or what happens if an invalid protocol is provided.

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 clearly identifies the tool as returning BNB Chain DeFi protocol TVL, which differentiates it from siblings like bnb_defi_yields (yields) or bnb_token_risk (risk). However, it lacks an explicit verb such as 'list' or 'get', making the action slightly implied rather than stated.

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 phrase 'Leave protocol empty for top-20 list' provides a clear usage condition for the protocol parameter, but there is no direct guidance on when to choose this tool over siblings like bnb_overview or bnb_defi_yields. No exclusions or alternative tool references are given.

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