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

Annotations only declare readOnly/idempotent/non-destructive, so the description adds real substance: collateral is locked at write time for an ask and fills only when a buyer takes it, an ask's premium is reduced by Borro's share, one share of stock vault collateral is locked per call share, and the flow does an exact approval then simulates from the wallet. It stops short of covering failure modes or the signing sequence after simulation.

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-loaded: the first clause says it produces unsigned transactions and the two routing modes come before the collateral mechanics. It is dense and parenthesis-heavy, but every clause carries a distinct fact (lock source, collateral vault, approval/simulation) rather than 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?

For a 9-parameter, no-output-schema prepare tool it covers a lot: what gets locked, from where, the ask-vs-bid branch, and the approval/simulation step. Remaining gap is that it never says what is returned (unsigned transaction objects to sign) nor which parameters pair with which mode (premium vs order_id exclusivity).

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 parameters are already documented (including the `from` default per option type and order_id replacing premium). The description restates the same choices at a higher level but adds no syntax or constraint detail beyond the schema, so the baseline of 3 applies.

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 names a specific verb and object: it returns unsigned transactions (prepared, not executed) for writing calls or puts, and it spells out the two ways to do it — post an ask at a premium or, with order_id, sell into an existing bid. That 'prepare' framing separates it from execution-oriented siblings like buy_option or settle_series without ambiguity.

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 gives clear decision context: omit order_id and supply a premium to post an ask; pass order_id to hit that bid immediately at its premium. It also states the defaults for the `from` source per option type. What it lacks is explicit exclusion language or prerequisites (e.g. required balance/position before writing).

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