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

With only readOnlyHint in annotations, the description carries the behavioral burden and does so richly: return shape, truncation semantics (consensus truncated, tickers_found full count), common-stock-only scope, per-fund latest-quarter variance, SEC EDGAR source with ~45-day delay, and caveats location.

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 purpose and scope are front-loaded in the first sentence, followed by compact return structure, parameter effects, caveats, and sourcing. Every sentence adds information; none is filler.

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?

There is no output schema, but the description fully explains the return object and row fields, truncation rules, source, and timing caveats. An agent has everything needed to call and interpret the tool correctly.

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 100% and the schema already documents defaults and caps. The description adds meaningful relational semantics: that top_n truncates the consensus list while tickers_found remains the full count meeting min_funds, which is not obvious from the schema alone.

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 first sentence states a specific verb-resource-scope: which tickers tracked 13F filers most widely hold in common. It clearly distinguishes itself from sibling get_13f_holdings by naming that tool and its different question.

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 maps the tool to 'who is buying X?' and contrasts it with get_13f_holdings ('what does fund X own?'), giving an agent a clear routing rule. It also states source and delay, which are relevant usage context.

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