filings_insider_summary

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

Annotations already declare readOnlyHint/idempotentHint/destructiveHint=false, and the description adds genuinely new context beyond them: it discloses the payment model (x402 USDC on Base or WICKEDAPI_API_KEY) and pre-empts a common misinterpretation by explaining that an HTTP 402 carries a price quote, not a failure. The "Behavior: read-only" line merely restates annotations, which keeps this 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 substantive content rollup and the sibling exclusion, followed by an example and payment note; every block is useful. Minor waste in the redundant "Behavior: read-only" restatement and a fairly dense opening sentence.

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 fully enumerates the returned fields (counts, dollar totals, net flow, distinct buyers/sellers, cluster flag, largest trades), covers the payment/error path, and covers both parameters. 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 coverage is 100% and the schema already documents both the required ticker and the days window including default 30 and max 90. The description adds only an example query string, not additional semantics such as ticker format or window edge behavior, so the 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 and resource — an insider-activity rollup for one ticker over a window — and enumerates the concrete contents (buy/sell counts, dollar totals, net flow, cluster-buying flag, largest trades). It also names the sibling it is not, filings_insider_trades, so an agent can distinguish it without opening schemas.

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?

Explicit when-to-use ("Use when you want a ticker's insider buying and selling rolled up over a window") plus an explicit exclusion and routing to the alternative ("Not for the underlying trades (use filings_insider_trades)"). Nothing is left to inference.

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