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

The description goes well beyond the annotations by explaining costs, lack of account/card requirement, automatic site reading, per-day/domain limits, future-date restrictions, and the risk of being outbid later. These are exactly the behavioral traits an agent needs to know, and nothing in the description contradicts the annotations.

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?

The description is well-structured and front-loaded with the core action, then expands to cost, constraints, and consequences. It is slightly wordy in places, such as 'so any amount takes it, zero included' and the closing 'nothing was lost with it,' but every sentence contributes useful context.

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 write operation with no output schema, the description covers cost, authentication, time constraints, rate limits, and failure consequences — enough for an agent to decide whether and how to invoke it. The main gap is the lack of any indication of what the tool returns on success, though the absence of an output schema makes this less critical.

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 the parameter schema already documents url, name, dayKey, tagline, category, and slotIndex thoroughly. The tool description adds no parameter-specific detail beyond the schema; it enriches the overall context but does not add meaning to individual parameters.

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 uses a specific verb-plus-resource construction: 'Put a product on the board in a slot nobody holds.' It clearly identifies the action, the target resource, and the key condition (free/unclaimed slot), and it is obviously distinct from the read-only sibling tools like get_board and get_slot_price.

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?

The description clearly states when this tool is appropriate: for free claims, with no account or card, limited to today or tomorrow, and one claim per registrable domain per day. It also hints at the alternative path for further-ahead bookings ('booking further ahead is for bidders on the site'), though it does not explicitly name a sibling tool as the alternative.

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