Chain TVL overview

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

No annotations are provided, so the description carries the full burden. It discloses that the tool is paid (up to $0.01 USDC per call via x402 on Base), which is a behavioral trait. However, it does not mention whether the tool is read-only, destructive, or any rate limits or permissions needed. The paid disclosure adds some value but leaves other behavioral aspects unclear.

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 followed by a billing notice, all front-loaded with key info. Every sentence is meaningful and concise. The structure is clean, with no redundant or excessive text.

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 simplicity of the tool (one optional param, no output schema), the description adequately states the purpose but does not explain the exact output format (e.g., whether it returns a list of chains with values or just one value). With no output schema, the description could be more explicit about what the user sees. It is minimally complete but leaves some ambiguity.

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 for the single optional parameter 'chain' (described as 'Optional chain name to filter'). The tool description reiterates this by saying 'per blockchain, or for one chain,' but adds no new semantic details beyond what the schema already provides. Therefore, it meets the baseline but does not enhance understanding.

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 uses a specific verb-resource combination: 'Total value locked per blockchain, or for one chain.' It clearly states the tool provides TVL data for blockchains and can be used to compare ecosystem sizes, distinguishing it from sibling tools like defi_tvl which focus on protocols.

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 explicitly says 'Use to compare ecosystem size,' providing a clear use case. However, it does not mention when not to use this tool or provide alternatives, which is a minor gap. The sibling list includes defi_tvl and other TVL-related tools, but no direct comparison is made.

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