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

With no annotations present, the description carries the full burden and does state 'Read only', which is the key safety fact. It also discloses that the wallet is used to check Disk balance and a daily limit, giving the agent the eligibility model. It does not cover failure modes or rate behavior, but the read-only claim is unambiguous and consistent with the schema note that nothing is sent from the wallet.

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?

Two dense sentences with the return fields front-loaded and no filler. However, terse fragments like 'sold and cap' and unexplained jargon ('Disk') cost some readability without saving much space.

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 exists, so the description must describe returns, and it does list the main fields plus the conditional 'reason if not' case. It is missing any explanation of what 'cap' means as a numeric field, which would matter for an agent interpreting the quote.

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 both parameters are already documented in detail, including the reassurance that the wallet is never debited. The description adds only the purpose of the wallet (Disk and daily-limit check), which is largely redundant with 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 the resource (apartments for sale) and enumerates exactly what the quote returns: price in ZENI, sold status, cap for levels 2-5, and buy-eligibility with a reason. It is distinguishable from the prepare_apartment_* siblings by being a read-only preview, though it never names those siblings explicitly to reinforce the split.

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?

'Pass your wallet for a quote that checks your Disk and daily limit' implies you call this before attempting a purchase, but the description never states that explicitly or points to prepare_apartment_buy as the follow-up action. Usage is inferable rather than prescribed.

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