defi_tvl

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

With no annotations provided, the description carries the full burden and does well by disclosing key behavioral traits: it specifies the return format (tvl, change metrics, chains, category), mentions the pricing information ('$0.002 USDC per call'), and clarifies the dual functionality (top 10 vs. specific protocol). It doesn't cover rate limits or error handling, but provides substantial operational context.

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, followed by structured sections ('Use when:', 'Returns:', 'Price:'), making it highly efficient. Every sentence adds critical information without redundancy, and the bullet-like formatting improves readability.

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 annotations and no output schema, the description provides strong contextual completeness: it explains the tool's purpose, usage guidelines, return values, and pricing. It could improve by mentioning data freshness or source reliability, but for a single-parameter tool with clear functionality, it covers most essential aspects well.

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 input schema has 100% description coverage, so the baseline is 3. The description adds value by explaining the semantics of the protocol parameter: it clarifies that leaving it empty returns the top 10, while providing a name/slug (with examples like 'uniswap', 'aave') fetches a specific protocol, enhancing understanding beyond the schema's basic description.

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 states the specific action ('Returns top 10 or a specific protocol') and resource ('DeFi protocol Total Value Locked from DeFiLlama'), distinguishing it from siblings like token_price or wallet_balance by focusing on TVL metrics rather than prices or balances.

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 'Use when:' section explicitly states when to use this tool ('need the Total Value Locked in a specific DeFi protocol or want to compare the top protocols by TVL'), providing clear context and distinguishing it from alternatives like dex_liquidity or dune_query that serve different purposes.

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