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

With no annotations, the description carries the full burden and does so well: it discloses the 30-day duration, one-time payment, the exact alert trigger conditions, that alerts are edge-triggered only ('only when something changes'), the $1 price, and the two-step 402-then-retry payment handshake with `_meta["x402/payment"]`. Gaps remain on repeat-call behavior (idempotency/duplicate watches) and cancellation, which matter for a paid subscription-like tool.

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 audience are front-loaded in the first clause, and every subsequent sentence carries real information (alert triggers, return value, price, payment mechanism). The long enumeration of trigger conditions in a single sentence is dense but earns its place given no annotations exist to cover it.

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?

No output schema exists, so the description usefully states the return value ('a public record page to link from your listing') and explains the payment protocol an agent must implement. For a 4-parameter nested-object tool with zero annotations, these are the critical unknowns, and the remaining gaps (cancellation, duplicate-watch behavior) are secondary.

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 the schema already documents `resource`, `method`, `network`, and the nested `notify`/`webhook`/`ntfy` fields. The description adds only contextual framing (one resource per watch, alert delivery via webhook JSON POST or ntfy topic), which is marginal over the schema — 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 — hourly sellercheck monitoring of one x402 resource for 30 days, paid once — and implicitly distinguishes itself from the sibling `sellercheck` (one-off check) by naming the cadence and duration. An agent can tell monitoring-subscription apart from single-check without opening the 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?

Scopes the audience ('For x402 sellers') and gives a clear condition for choosing the alternate path: use an x402-aware MCP client, or fall back to `npx -y crosscheckapi` if none is available. It does not explicitly say 'use sellercheck for a one-time check 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.