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

With no annotations at all, the description carries the full load and does it well: 30-day or 300-alert expiry, HMAC-signed payloads, a mandatory $0.50 USDC on Base payment via x402 in-band, and an alternate REST endpoint. Payment and lifetime constraints are exactly the kind of behavior an agent must know before invoking.

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-loads the core action and scope in one dense sentence, then lists args and payment/endpoint details compactly. Tight, though the payment and URL tail is a little crammed together.

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 and no annotations, so the description must be self-sufficient, and it covers lifetime, signing, payment, and the callback contract. It stops short of describing payload shape or whether duplicates/retries occur, but an agent has enough to call it correctly.

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 0%, so the description must compensate, and it partially does: it pins webhookUrl to public https, marks pairs as optional, and documents the filter enum values. It still never explains the pairs format (symbols vs pair ids) or defaults when filter is omitted, so coverage remains incomplete.

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 (Subscribe) and resource (a public https webhook to NEW green WaveTrend band dots), including the trigger condition and delivery window. It is trivially distinguishable from every sibling, all of which are read-style get_* tools.

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?

The description implies when to use it (to receive alerts on new green dots) and names an alternate transport (the raw POST endpoint), but gives no explicit when-not-to-use or guidance for choosing among the sibling signal tools for someone who only wants to query dots.

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