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

Annotations already declare read-only/open-world, but the description adds substantial behavior: ordering ('most serious first'), inclusion thresholds ('$100K+ insider purchases'), exclusions ('SPACs left out'), and a full billing model ('charged only when a result is returned: invalid input (400) and upstream failures (4xx/5xx) are not settled', $0.025 USDC via x402). The per-call charge is consistent with idempotentHint=false.

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 and front-loaded with the user-intent phrasings before the mechanics. Slightly long for a single paragraph, and the x402/price sentence partially duplicates server-level instructions, but nearly every clause carries operative 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 compensates by describing the return ('Starts with a few plain-sentence `summary` lines') and the four sections with their content. Combined with defaults and the subscription pointer, 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% and the schema already documents each parameter, its defaults, and its effects. The description's parameter sentences ('narrow alerts and earnings to a watchlist', 'pick sections') largely restate that, so the baseline 3 applies rather than true added value.

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 aggregated resource ('One call combines') and enumerates exactly what it pulls together: recent SEC alerts, latest earnings, weekly IPOs, and macro indicators. An agent can distinguish it from siblings like sec_earnings_today, sec_ipo_filings, or economic_indicators without inspecting 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?

Opens with the concrete questions it answers ('What happened in the markets...', 'Give me a morning briefing'), explains how to narrow via tickers/include, and explicitly names the alternative for recurring use: 'For one every morning on your webhook, use daily_briefing_subscription.' Timing and payment conditions are also stated.

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