hl_user_fills_by_time

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

With no annotations provided, the description must carry the full burden of behavioral disclosure, but it only states the time range. It does not mention inclusivity of endpoints, ordering, pagination, or the effect of aggregate_by_time, which is a significant transparency gap for a tool with optional behavior.

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 a single, front-loaded sentence with no fluff, making it concise and easy to skim. However, the parenthetical '(userFillsByTime)' is redundant and adds no value, preventing a perfect score.

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 the tool has four parameters and a likely complex output schema, the description is too sparse. It fails to explain aggregate_by_time, which likely alters the result structure, and does not clarify the user identifier format or how results are ordered. This is a moderately complex tool, and the description is inadequate for full agent comprehension.

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 coverage is 0%, so the description must compensate, yet it only references start_time_ms and end_time_ms without adding meaning, and it omits user and aggregate_by_time entirely. This leaves two of four parameters unexplained, and even the time parameters lack details like whether times are inclusive or what units are used.

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 resource as user fills bounded by start_time_ms and optional end_time_ms, making the tool's purpose evident. Though it lacks a formal action verb like 'retrieve', the noun phrase is unambiguous and sufficiently distinguishes it from sibling tools like hl_user_fills without a time window.

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 usage context is implied by the time-range description: use this tool when you want user fills within a specific time window. However, it does not explicitly mention alternatives or when not to use it, such as hl_user_fills for unfiltered fills, which would have strengthened the guidance.

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