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

Annotations flag this as read-only, idempotent, and non-destructive, and the description is consistent with that by explicitly saying it returns unsigned transactions rather than executing. It adds genuinely useful non-annotation detail: pricing happens now, simulation is sequential from the wallet, an approval step precedes execution, and the long leg earns lending fees while held.

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?

A single dense sentence that front-loads the deliverable (unsigned transactions) and the pair mechanics, with the timing/simulation note appended. The parenthetical about lending fees is informative rather than filler, though the sentence is long enough to require careful parsing.

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 6-parameter, no-output-schema preparation tool, the description covers what is produced (unsigned transactions), the ordering (approvals first, simulated in sequence), and when pricing occurs. What is missing is modest: no mention that deposit is optional or what it defaults to, and no hint of failure modes such as insufficient balance.

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 all six parameters are already documented in the schema with format examples. The description explains the roles of the long and short legs but adds no format or constraint detail for wallet, amounts, or the optional deposit beyond what the schema states.

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 deliverable (unsigned transactions) for a specific operation (a pair trade with a long leg and a short leg), which cleanly separates it from open_long, open_short, and close_pair. The two-leg mechanics are spelled out rather than implied.

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?

'approvals first' and 'simulated from the wallet in order' convey sequencing, which is real usage context. However, it never says when to prefer this over calling open_long and open_short separately, or how it relates to close_pair, so the agent must infer the boundary.

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