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

Annotations already declare read-only, non-destructive, open-world behavior, but the description adds meaningful context beyond them: the return shape (one point per day, oldest first, fee-inclusive dollars), the recording policy (only tracked events), and the important caveat that an empty history is a real, common answer rather than a flat line.

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 front-loaded with usage cues before explaining return semantics and caveats. Every sentence contributes either routing guidance, output meaning, or an important limitation, with no filler.

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?

Given an existing output schema, the description need not detail return values, yet it still clarifies the output semantics and the empty-history edge case. Together with the rich annotations and full schema coverage, an agent has everything needed to call this tool correctly.

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 both parameters (`event_id`, `days`) are already documented in the schema, including the default and range for `days`. The description adds no parameter-level syntax or format beyond what the schema provides, so the baseline score of 3 is appropriate.

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 states a specific verb and resource ('Returns the daily closing get-in price') and clearly scopes what the tool does over time. It explicitly distinguishes itself from the sibling `get_recent_sales` by contrasting asking-side history with actual sale prices.

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?

It gives explicit trigger conditions: rising/falling prices, buy-now-vs-wait decisions, and recent event behavior. It also names the main alternative (`get_recent_sales`) and warns against conflating the two, which is exactly the routing guidance an agent needs.

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