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

Beyond the annotations it discloses the fee waiver, single-transaction behavior, that results are simulated from the wallet, the EIP-5792 batching, and the sign_url for a human owner. 'Nothing is sent' reconciles the apparent move/readOnlyHint tension, so there is no contradiction. It stops short of describing failure modes when no counterpart vault exists.

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?

Three dense sentences, front-loaded with the action and its condition, then the return shape, then the safety statement. No filler.

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?

No output schema, yet the description explains the return payload (unsigned txs, batch form, sign_url) and that nothing is broadcast. Precondition handling for the missing-counterpart-vault case is the only real gap.

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 the four parameters, their patterns, and which are optional are already documented. The description only adds the 'same pair' constraint tying to_vault to vault, which is marginal added value over 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+resource ('Move a position to another open Panda vault for the same pair in one transaction') and constrains it in a way that separates it from build_vault_deposit, build_vault_withdraw, and build_old_vault_migrate. An agent can tell what the tool does without opening the schema.

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 parenthetical '(only when such a vault exists)' gives an explicit applicability precondition. It does not, however, name the nearest alternative (build_old_vault_migrate) or say what to do when no such vault exists, so routing is implied rather than spelled out.

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