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

With no annotations provided, the description carries the full burden. It discloses that the tool is free and read-only, explains the significant cost differences (over 1000x), and clarifies that internal transfers are unaffected. This goes beyond basic safety and gives useful behavioral context, though it does not describe the exact output format or error handling.

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 concise (~80 words), front-loaded with 'Free and read-only,' and every sentence serves a purpose: explaining the ranking, cost disparity, single-chain option, and internal transfer exception. It is well-structured and avoids redundancy.

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 simple two-parameter preview tool, the description adequately covers purpose, behavior, and edge cases (internal transfers). It mentions that toChain can indicate success, and the ranking implies a return list. It does not specify the exact response structure, but no output schema exists and the tool is straightforward, so this is acceptable.

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%, so the schema already documents both parameters. The description adds some contextual framing (e.g., amount is for the withdrawal, toChain limits to a single chain) but does not provide substantive new meaning beyond what the schema already states. Hence the baseline score of 3 is appropriate.

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's function: given an amount, it ranks every exit chain by what actually arrives after destination payout costs. This is a specific verb+resource+scope combination that distinguishes it from sibling tools like robyn_netting_transfer_payload or robyn_cross_chain, which handle actual movements rather than previews.

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?

It provides clear context: use to preview netting withdrawals, and pass toChain to price a single chain. It also gives an explicit when-not-to-use: internal transfers between netting accounts are free and not subject to these costs. However, it does not explicitly name alternative tools for those cases, so it falls short of a 5.

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