DeFi total value locked

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

Annotations already declare read-only, idempotent, open-world, non-destructive behavior, so the description's job is lighter. It adds useful mode-specific output context (share, rank, top protocols, category, 1h/1d/7d change), though it omits freshness, rate limits, or error behavior.

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?

Three tightly written sentences, front-loaded with the tool's purpose, then the three usage modes. Every sentence earns its place.

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?

No output schema exists, so the description must carry return-shape burden; it does so at a useful summary level for each mode. It could be more complete about response structure and the `limit` control, but it is sufficient for correct 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 is 100%, so syntax is already covered, but the description adds semantic meaning by explaining what each argument causes the response to contain. It does not explain the `limit` parameter, keeping it below 5.

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?

Names a specific metric and source ("DeFi TVL from DefiLlama") and clearly distinguishes itself from siblings like get_price and get_derivatives by focusing on protocol/chain locked value.

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?

Explicitly maps the three argument modes to outcomes: no args for top chains and share, `chain` for chain TVL/rank/protocols, `protocol` for protocol TVL/category/change. It does not name when to use a sibling instead, so it falls just short of full when/when-not guidance.

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