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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds behavioral context beyond that: it clarifies that Δ Value includes the quarter's price move on held shares, advises using Δ Shares to read the position change itself, and discloses that the output starts from the first complete 13F quarter and refuses comparisons crossing that boundary. This adds valuable nuance about output semantics and data limitations.

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 four sentences long, each carrying substantive information: the main definition, bucket mechanics, the Δ Value caveat, and the corpus boundary. It avoids filler and front-loads the primary action, though it could be slightly more structured with lists or breaks.

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 is moderately complex with four distinct modes and a subtle data caveat. The description covers all modes, the caveat, and the boundary condition, and it provides a concrete use case. With no output schema, it would benefit from a brief note on output structure, but the expected leaderboard format is reasonably implied.

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 input schema already describes all three parameters with details such as bucket enum values, maxResults default (20) and clamp (1-500), and reportDate snapping behavior. With 100% schema coverage, the description need not repeat these; it only adds bucket ranking context, which is helpful but not critical. Baseline 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 opens with a specific action: 'Get the market-wide 13F leaderboards for a given quarter' and enumerates the four bucket types (top-buys, top-sells, new-positions, sold-out-positions). It explicitly differentiates from siblings by scoping to 'across all 13F filers' and by naming 'market-wide' versus tools like GetTopBuyersSellers or GetMarketWideCongressionalActivity.

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 description gives an explicit use case: 'Use this to answer "what's the consensus 13F move this quarter?"' It also explains the available buckets and the boundary behavior, providing clear context. However, it does not name alternative tools or state when not to use it, so it falls short of full exclusion guidance.

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