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

Goes well beyond the annotations: discloses the exact price ($0.005 USDC via x402 on Base), the no-API-key/no-account auth model, the failure mode ('calling without payment returns 402 with the payment requirements'), and the 7-day polling window. These are precisely the operational facts — cost, auth, error behavior — that readOnlyHint/idempotentHint flags cannot convey.

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?

Purpose and polling window are front-loaded, and the pricing/payment sentence earns its place by preventing a failed-call surprise. The free-alternative sentence is longer than needed and slightly dilutes the core call guidance, keeping it from a 5.

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?

For a 5-parameter mutating watch tool with no output schema, the description covers cost, persistence window, auth, and the unpaid-request failure path. It omits how results are later retrieved (the poll_alerts path) and what the webhook push payload/signature looks like, which an agent creating a watch would want to know.

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 cik/ticker, forms, webhook, and idempotency_key are already documented in structured data. The description adds no parameter-level meaning (no note on ticker-vs-cik precedence or form filter defaults), 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 ('Monitor a company ... for new SEC filings, decoded 8-K events, and parsed Form 4 trades') plus the distinguishing trait of persistence 'between agent runs' with 7 days of polling. That implicitly separates it from the one-shot check_sec_filings sibling, but it never names that sibling, so the differentiation is inferred rather than stated.

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?

Gives clear usage context ('between agent runs' = persistent watch) and points to concrete free alternatives (the /demo sample and the 24h /try watch) when payment is a barrier. It does not explicitly say when to prefer check_sec_filings or create_watch instead, so the sibling routing 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.