list_winners_losers

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

With no annotations, the description must disclose behavioral traits. It mentions 'deltas pre-computed' but does not state whether the tool is read-only, requires specific permissions, or has side effects. This is insufficient for understanding the tool's 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?

While brief, the description is incomplete. It fails to convey necessary invocation details, making it under-specified rather than concise. Every sentence should earn its place, but this one leaves critical gaps.

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 no output schema, no annotations, and a minimally descriptive input schema, the description is incomplete. An agent cannot reliably use this tool without knowing how to specify the two periods or the target (keywords/pages).

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?

The schema has 0 defined parameters but allows arbitrary properties (additionalProperties: true). The description adds no parameter information, leaving the agent clueless about which parameters (e.g., period1, period2, scope) are expected or valid.

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 'Biggest movers between two periods (keywords or pages), deltas pre-computed.' clearly identifies the tool's function, distinguishing it from sibling list/comparison tools by specifying the winners/losers aspect and the scope (keywords or pages).

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 guidance is provided on when to use this tool versus alternatives (e.g., compare_date_ranges, get_top_keywords). The description omits how to specify the two periods or select keywords/pages, leaving the agent without invocation context.

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