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

With no annotations provided, the description carries the behavioral burden itself. It clearly discloses authentication requirements (API key as bearer token), a fallback payment-based access path, the valid chains, default and max window, and the contents of the result. It does not explicitly state rate limits or elaborate on payment mechanics, but it gives enough for an agent to understand cost and scope.

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 packs necessary details into a compact paragraph with no filler. The payment/prerequisite clause is dense and comes first, which is arguably important context but elongates the opening sentence. Everything else is efficiently stated.

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?

For a tool with two optional parameters, an output schema, and no required inputs, the description covers the important execution details: authentication, cost alternative, accepted chains, window semantics, and output content. An agent has enough information to call the tool correctly without inspecting the output schema.

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 0%, yet the description fully compensates: it explains the meaning of window, imposes units/default/max boundary, documents that l2 is optional, names every valid enum value, and clarifies the 'all chains' behavior when l2 is omitted. This is valuable semantic context that the schema alone cannot provide.

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 identifies the tool's domain: Layer 2 bridge activity across arbitrum, base, and optimism, with specific output dimensions like deposits, withdrawals, message counts, and value moved in ETH. Although it lacks an explicit verb such as 'get' or 'return', the meaning is clear. It is reasonably differentiated from siblings like stablecoin_flows or whale_flows by focusing on bridge-specific activity.

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 gives useful parameter guidance: window is in hours, default is 24, max is 720, and omitting l2 returns all three chains. However, it does not explicitly say when to prefer this tool over alternatives such as stablecoin_flows or whale_flows, so the guidance is context-focused rather than comparison-focused.

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