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

With annotations declaring only the generic mutation profile (readOnly=false, idempotent=false, destructive=false), the description supplies the real behavioral picture: pre-flight checks (property live, wallet doesn't hold it), warning conditions (far from estimate, listing at/below offer, collateralized), a 15-minute expiry, payload null for now, and the explicit safety statement that the server holds no keys and submits nothing.

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?

Purpose and the 'prepared, not sent' distinction are front-loaded, and every sentence carries information. It is a dense single block with several clauses stacked into long sentences, which slightly hurts scannability but not comprehension.

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 carry the return contract — and it does, enumerating signRequest contents (summary, warnings, signLink, expiresAt, payload) and explaining the persisted state. Combined with the warning and pre-check behavior, an agent has everything needed to call and interpret this tool.

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 five parameters are already documented in the schema, including the wallet pattern and the expiresDays default of 14. The description mostly restates that coverage ('wallet is the address that will sign'), adding only the note that the sign page restricts signing to that wallet — a marginal gain over the schema baseline.

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 an offer to buy a minted property on Fabrica') along with the payment mechanics (USD amount paid in USDC). The framing 'Prepared, not sent' immediately separates it from execution siblings like buy_land or accept_land_offer, so an agent can distinguish it 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?

Gives clear context for when this applies: the offer is prepared and stored so the sign page can load it, and nothing happens until the person signs. It does not explicitly name the alternative sibling tools (e.g. buy_land for immediate purchase, accept_land_offer for the counterparty side), so it stops just short of full when/when-not/alternatives guidance.

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