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

With no annotations, the description carries the full burden and does substantial work: it discloses the 30-day lifetime, that the webhook is signed with a secret issued once, that a 2xx test ping is required or the caller is not charged, and the $0.10 x402/USDC cost. Undisclosed behaviors remain — delivery retry policy, what happens on a failed ping response body, and the mechanism for later retrieving or rotating the signing secret.

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 core identity, then compact per-type clauses, then commercial terms. Dense but every sentence carries information; the parenthetical-heavy style makes it slightly run-on but nothing is padding.

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?

Six parameters, no annotations, no output schema, and two enums the schema barely documents. The description covers the important behavioral and cost surface but leaves real gaps for a stateful, paid subscription tool: how the signing secret is delivered, whether multiple subscriptions can coexist, and how to stop an alert. Adequate but not complete.

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 only 17%, so the description must compensate. It explains the meaning of market_id and threshold (points, default 15) and keyword/category for new_market, plus that webhook_url must be https — that is genuine added meaning. It omits the documented threshold bounds (5-50), keyword length limits, and assigns no semantics to the 'type' discriminator itself.

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?

Opens with a specific verb+resource ('Webhook alerts for 30 days') and then enumerates the two subscription types (market_move, new_market) with what each triggers on. An agent can tell this creates a persistent alert subscription, distinct from alert_cancel/alert_status. It never names those siblings, so differentiation is implied 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?

The type descriptions effectively explain which subscription to pick for odds-movement monitoring vs new-market discovery, which is real usage guidance. However, it gives no explicit when-to-use vs alert_status/alert_cancel, no prerequisites, and no guidance on how many alerts are reasonable or when a subscription should be cancelled.

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