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

Annotations already cover read-only, non-destructive, open-world and non-idempotent behavior; the description adds genuinely new context with cost semantics ('$0.01/call via x402 USDC or a card key, first 25 free; failed calls free') and the warning that 'each call is charged, so repeats are not free,' which explains the idempotentHint=false in practical terms. It does not discuss latency, rate limits, or how long a PENDING result may take to resolve.

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?

Front-loads purpose and scope in the first clause, then layers states, use case, example, pricing, and safety notes. The long sample hash is the bulkiest element but serves format clarity; the parenthetical router list and dual pricing mention border on padding.

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?

With no output schema, the description carries the burden of describing returns and does so thoroughly: status values, sub-status and message, both transaction hashes, chains, tokens, amounts, and explorer links. Combined with pricing, failure-state coverage (NOT_FOUND), and the read-only assurance, nothing essential for correct invocation is missing.

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 coverage is 100%, so both parameters are already documented in structured form; the description only adds a concrete example hash that clarifies the expected format. The optional fromChain parameter is never mentioned in the description, so no extra meaning is layered on top of the schema.

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 and resource: retrieve the status of a cross-chain transfer by source transaction hash. It enumerates the supported routers (LI.FI, Stargate, Across, CCTP, Hop, Polymer) and the exact return states (DONE, PENDING, FAILED, NOT_FOUND), which clearly separates it from bridge_quote and other siblings.

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?

Explicitly gives the operational context: 'Use to check whether funds arrived before an agent continues,' which tells an agent when to reach for it. It does not name an alternative or state when-not to use it (e.g., for quotes use bridge_quote), so it stops short of full routing guidance.

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