Rank blockchains by total DeFi TVL

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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, covering safety and idempotency. The description adds the pricing detail ($0.002 per call), which is a behavioral constraint beyond what annotations express. It doesn't describe return format or pagination, but as a read-only ranking with a single parameter, the behavioral profile is well-enclosed.

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 two sentences with minimal waste. The first sentence clearly states the purpose. The second sentence adds pricing, which is relevant context. However, the pricing information might be better placed in annotations or outside the core tool description, slightly reducing focus.

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 the tool is simple (one optional parameter, no output schema, reads only), the description is almost complete. It lacks details about what the output looks like (e.g., which fields are returned: name, TVL, rank?). However, with no output schema, this is a minor gap. The tool's simplicity makes the missing output format less critical 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 description coverage is 100% (the 'limit' property has a one-sentence description defining range and default). The description does not add any parameter-specific semantics beyond what the schema provides. Baseline score of 3 is appropriate since schema already documents the single parameter adequately.

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 tool ranks blockchains by total DeFi TVL. The verb 'ranks' combined with the resource 'blockchains by total DeFi value locked' is specific and fully distinguishes it from siblings like 'get_defi_protocol_tvl' which returns data for a single protocol.

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 description provides no guidance on when to use this tool versus siblings. Notably, the sibling 'get_defi_protocol_tvl' does a related but different function, yet no comparison or when-to-use/not-to-use advice is given. The only usage-adjacent detail is the limit parameter default, but this is about how to use, not when.

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