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

Annotations already establish a read-only, closed-world read, so the description's job is data semantics — and it delivers: default 50 rows with a limit knob, and the important warning that rows with change=listing or non_trade=true are not market trades and must be excluded from trade totals. It does not cover pagination beyond limit or ordering stability, which keeps it from a 5.

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?

Front-loaded with the resource and timeframe, then filters, then the sibling alternative, then caveats — a sensible priority order with no filler. It is dense to the point of being crowded, packing five distinct ideas into one paragraph, but every sentence carries information.

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 correctly spends its words on returned-field semantics — the meaning of change values and the kind taxonomy (buy, placement, control, non_trade, unknown) for 5% filings. An agent could call it and interpret results correctly; only the full field list and result-count/pagination behavior are left unstated.

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 80%, so the schema already documents days, limit, ticker and entity_id defaults. The description largely restates those defaults, adding only that holder and entity_id act as owner-level filters (implying they compose with ticker). That is a small increment over the schema, consistent with the baseline 3 for well-covered schemas.

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 and resource: a feed of ownership-change filings from the last N days, newest first, and frames its scope as cross-ticker ('who bought and sold this week'). That scope statement is exactly what separates it from the single-entity siblings, so an agent can pick it without opening any schema.

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 names when to use it (cross-ticker weekly activity), how to narrow it (ticker for one symbol, holder/entity_id for one owner), and names the alternative with its condition — use get_holder_history when the full history of a single ticker without a date limit is needed. When-not guidance is present, not merely implied.

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