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

Annotations already declare readOnlyHint=false, destructiveHint=false and idempotentHint=true. The description usefully adds that it never sends anything and that the user signs in their wallet, which explains why a non-read-only tool has no real side effects. It does not say whether the generated link expires or what happens if the offer is no longer open, which is the remaining behavioral gap.

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 with the verb and resource, which is good, but the closing two clauses ("Does not send anything" and "Prepares only; never sends") restate the same fact twice. One of those could be dropped without losing information.

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?

With no output schema, the description compensates by describing the return payload (price/goods preview plus buy-dialog link), which is exactly what the agent needs. For a one-parameter preparation tool this is close to complete; only failure conditions and link lifetime are unaddressed.

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?

One parameter at 0% schema description coverage; the schema only supplies a digit pattern, so the description must carry the semantics. It does add the key constraint that the target must be an open offer, but never says what the id identifies (offer id) or that the offer must not be expired or already accepted.

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 buying an open offer") and goes further to say what it returns: a preview of what the buyer pays and gets plus a kyte.sh link that opens the buy dialog. That is concrete enough to distinguish it from the other prepare_* siblings. It stops short of naming which alternative to pick when the user wants a different option type.

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?

Implies usage (buy an open offer) and clarifies the terminal step is signing in the user's wallet, but never states prerequisites such as needing a valid open offer first, nor names an alternative tool for other offer types. An agent can infer the when from the name plus description, but nothing is explicit.

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