get_trend_series

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds minimal behavioral context—'rank and hot-value trends' hints at the return shape but not at time-bucket granularity or how since/until defaults behave. There's no contradiction, but the description doesn't substantially enrich beyond 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 a single efficient sentence that front-loads the core purpose. It's appropriately concise with no filler. However, it's so terse that it sacrifices informative content—a slightly longer description that covers time-range parameters would be more valuable without risking verbosity.

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?

The tool has 6 parameters with 0% schema coverage, but an output schema exists, which somewhat offsets the need to explain return values. For a trend-series tool with time-range and bucketing parameters, the description omits critical information about how since/until/bucket shape the data. The single-sentence coverage of 'rank and hot-value trends for one historical item' is plausible but leaves the time-domain semantics unexplained, making this marginally adequate.

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 0%, so the description must carry the full burden of parameter meaning. It mentions 'rank and hot-value trends' and a single historical item (implying site, board_key, item_id), but it fails to explain the time-related parameters (site, since, until, bucket). The 'bucket' enum ('10m','1h','6h','1d') is structural but its effect on the returned series isn't described. The description only loosely covers the three required params and none of the optional ones.

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+resource ('Get rank and hot-value trends') for a single historical item. It's reasonably clear, but 'for one historical item' is vague—it doesn't clarify whether 'item' refers to a product, a search term, or another entity. The description doesn't explicitly differentiate from siblings like query_history or search_history, though 'trends for one item' hints at a narrow single-item scope.

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?

No explicit guidance on when to use this tool vs alternatives. Siblings include query_history and search_history, which likely relate to the same data domain, yet no distinguishing phrase or exclusion is given. The description implies a use case (viewing historical trend series) but provides no context on prerequisites, such as needing a board_key and item_id obtained from another tool first.

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