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

Annotations already mark the tool as readOnly and non-destructive. The description goes beyond annotations by explaining the actual pricing rule: zero if unheld, otherwise the minimum bid threshold. This gives the agent meaningful behavioral information about the returned value without contradicting 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?

One tightly written sentence conveys the essential pricing rule without waste. The most important information is front-loaded, and every phrase contributes to understanding what the tool returns.

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 simple two-parameter read-only tool with complete schema coverage, the description covers the return semantics clearly enough. It could be more complete by stating the output format or units or by naming sibling tools, but the annotations and schema cover the remaining operational context.

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 schema already documents dayKey and slotIndex sufficiently. The description adds the concept of 'specific slot' and 'cost to take' but does not add parameter-level detail beyond the schema.

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 clearly identifies the tool's purpose: returning the current price to take a specific slot, including the zero-price case and the amount a bid must beat. It is specific and useful, though it does not explicitly contrast itself with sibling tools like claim_free_slot or get_board.

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 phrase 'right now' and 'a bid has to beat' imply the tool is for checking current pricing before claiming or bidding on a slot. However, there is no explicit guidance on when to choose this tool over siblings, nor any exclusion such as 'use get_board for an overview' or 'use claim_free_lot to claim a slot.'

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