Most Widely Held Stocks

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

Annotations only declare readOnlyHint=true, but the description adds substantial behavioral context beyond that: valuation uses report-date closing prices with fallback to filer values, zero can appear for unavailable valuations, only the first complete report quarter is published, and during the newest quarter's open filing window non-filers carry prior-quarter positions. This is unusually rich disclosure.

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?

Dense but front-loaded, leading with the core purpose before folding in caveats and routing. Every sentence carries information; it is tightly packed rather than padded, though the volume of caveats makes it slightly heavy.

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?

With no output schema, the description compensates by naming the returned fields (Δ filers, total value, Δ value, share of the 13F universe) and explaining valuation fallbacks and availability limits. An agent has everything needed to call and interpret it.

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 the schema already documents sort, maxResults, and reportDate in detail (including the off-quarter snapping behavior). The description restates the sort dimensions but adds little syntax or format detail beyond the schema, so baseline 3 applies.

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?

States a specific verb+resource with scope: 'cross-sectional ranking of stocks by institutional 13F breadth for a quarter.' It clearly distinguishes itself from the sibling GetMarketWide13FActivity by explaining that only currently-held stocks rank here and sold-out names belong there.

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?

Explicitly routes the agent: names GetMarketWide13FActivity as the alternative for sold-out names, and flags when rankings/deltas are unavailable (pre-first-complete-quarter, boundary quarters). The conditions that select alternatives are spelled out.

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