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

Annotations already declare readOnly, idempotent, safe. Description adds valuable context beyond them: source (api.llama.fi/protocols), keyless auth, timestamped output, capped list behavior (default 50, max 200), and the surprising cost (0.01 USDC per call via x402 on Base). This is substantial behavioral disclosure not in annotations.

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?

Single dense sentence, front-loaded with the core purpose. Includes essential metadata compactly. Slightly congested with multiple details, but every part serves a purpose.

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, so description needn't detail returns, but it does mention the fields (rank, chain, category, 1d/7d change). Given annotations cover safety, the description provides source, auth, limit behavior, and cost. Complete enough for an agent to call correctly; minor gap: no explicit error behavior or rate limit details.

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?

Only 1 parameter with 100% schema description coverage, so baseline is 3. The description adds example usage 'via {"limit":N}' and explains the default and max values, adding some meaning beyond schema, but schema already describes the parameter as 'product parameters (JSON or text)' with the same example.

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?

Specific verb+resource: 'Top DeFi protocols by TVL with rank, chain, category and 1d/7d change'. Clearly distinguishes itself from siblings like defi_yields (yield-focused) and stablecoin_supply (stablecoins). An agent knows exactly what this returns.

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?

No explicit when-to-use or alternatives mentioned. Implied usage from TVL ranking context and default/max limit. Could name defi_yields as the alternative for yield queries, but doesn't. Usage is inferable but not guided.

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