defi_tvl

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

Discloses cost per call, caching behavior (up to 5 minutes), data freshness indicator (meta.fetchedAt), and that it aggregates across chains. No annotations, so description fully carries burden.

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?

Concise at ~100 words, front-loaded with purpose. Includes key details (cost, caching) without excessive verbosity.

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?

Simple tool with one parameter. Describes return value (TVL in USD) and freshness indicator. No output schema, but explanation suffices for agent invocation.

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 100% with one parameter. Description adds value by specifying slug source (defillama.com/protocols), lowercase requirement, and examples beyond schema 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?

Clearly states verb 'Get' and resource 'total value locked (TVL) in USD for a DeFi protocol'. Specific about using DefiLlama slug. Distinguishes from siblings like crypto_price or dex_pool.

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?

Provides explicit use cases (protocol health checks, DeFi rankings, risk screening, market research). Does not explicitly exclude alternatives but context signals indicate distinct purpose.

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