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

No annotations provided, so the description carries the full burden. It discloses the pricing model ($0.01 per call via x402), which is valuable behavioral context. However, it doesn't state whether results are cached, rate-limited, or what the response contains.

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?

Efficient single sentence with purpose plus examples and pricing in parentheses. Front-loaded with the core purpose. No wasted sentences, though the parenthetical pricing info could arguably be separate.

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 2-param lookup tool with 100% schema coverage, this is adequate but not rich. No output schema exists, so the description should explain what 'routes' means as a return value (list of bridges? quotes? fees?). The gap between input and expected output is undocumented.

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% and both parameters are documented (symbol, from_chain as lowercase strings). The description adds the example 'USDC from arbitrum' which reinforces format but adds little beyond the schema. Baseline 3 when schema does the heavy lifting.

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?

States a specific verb-like resource ('cross-chain route availability for a stablecoin from a given chain') with clear scope (bridge/venue coverage). Distinguishes itself reasonably from siblings like barker_execution_quote, though it doesn't explicitly name which sibling is the alternative.

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?

Provides example queries ('bridge USDC from arbitrum', '跨链路径') that signal when to use it. However, it doesn't state when NOT to use it or explicitly contrast with barker_execution_quote or other routing siblings.

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