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

With no annotations, the description carries the burden and does well: it discloses that the transaction is unsigned (nothing is signed or sent), that permissionless callers are acceptable, that the caller only pays gas, and that the outcome is a public draw rather than sender-controlled. It stops short of stating what happens if called before the drand round lands (revert vs. no-op) or whether the prepared flip can be replayed.

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 tight sentences: the first identifies the action and its trigger, the second kills the main agent-side doubts (who may call, who pays, who wins). No filler or restatement of the name.

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 prepare/simulation tool with no annotations and no output schema, the description covers the safety profile and permission model an agent needs before calling. The only gap is the shape of the prepared payload returned (unsigned tx object and what the agent should do with it), which is implied by '(unsigned)' but not spelled out.

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% and the wallet field already explains that nothing is sent from it, so the schema does the semantic work for both parameters. The description adds no format or constraint detail beyond that, which is the baseline expectation.

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 (prepare, unsigned) applied to a specific resource (flipping a sealed Red Dragon high table), plus the trigger condition (drand round published). It is clearly distinguishable from the neighboring prepare_red_dragon_join / _leave / _refund tools by naming the flip action and the sealed-table object.

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?

"once its drand round is published" gives the precondition for calling, and "Anyone may send it" clarifies there is no privileged caller requirement. It does not explicitly route the agent to a sibling (e.g. join/leave/refund) when the table is not yet in the flip phase, so it falls short of a full when/when-not statement.

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