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

With no annotations, the description carries the full burden, and it does disclose key traits: the operation is unsigned/preparatory, costs ZENI, requires an approval and a rank gate. However it never says what 'prepare' actually produces (a transaction to sign? a pending order?) or how the purchase is finalized, which is important for a no-annotation mutation-adjacent tool.

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, front-loaded sentence with no wasted words; the parentheticals pack in the id range, the currency and the approval prerequisite. It is telegraphic to the point of being slightly cryptic, but nothing is 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?

There is no output schema and no annotations, so the description should ideally explain what an unsigned preparation returns and how it connects to a subsequent approve/submit step. It hints at this via 'approve first' but leaves the resulting object and the completion path for the agent to infer.

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% and the schema already explains both parameters, including that the wallet is only read from and simulated. The description's only genuine addition is pointing to arsenal_shop to enumerate valid weaponIds, so baseline 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?

States a specific verb and resource ('prepare (unsigned) the purchase of a Season 2 weapon') and scopes it to weapons costing ZENI, which separates it from prepare_vehicle_buy and prepare_apartment_buy. It also routes the agent to arsenal_shop for the actual weapon list rather than leaving the id space unexplained.

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?

Gives two concrete preconditions: an approval step must happen first and the caller must hold the Stash rank the weapon lists. What's missing is an explicit statement of when not to use it (e.g. wrong season weapon, insufficient rank handling) or which sibling performs the follow-up approval.

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