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 enumerates the return states, discloses the settlement proof mechanism and file, names its upstream dependencies, and specifies failure behavior (refusal with no charge). Missing only auth/permission requirements and any rate-limit detail, so not quite a 5.

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 verb+resource and return states in the first clause. The subsequent sentences each carry distinct information (proof, dependencies, failure, price), though the SKU/x402 jargon makes it denser than ideal.

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 or annotations, the description compensates well by describing return states, cost, failure semantics, and dependencies. It is nearly complete for a single-param tool, lacking only explicit permission/authentication context.

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?

Single parameter with 100% schema description coverage, so the schema already documents it and the baseline is 3. The description adds no syntax or format guidance for the 'task' field beyond what the schema provides.

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 ('Defines a custom price/event alert') and what it returns ('current trigger state — armed, fired, or stale'). Explicitly differentiates itself from siblings by declaring it is 'the trigger layer, not the data layer' and naming oracle.volatility-monitor and oracle.price-feed as its inputs.

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 context for when this layer applies versus the data-layer siblings it reads from, and states a concrete exclusion rule ('Refuses, with no charge, when live price + buyer threshold fields cannot be fetched'). It stops short of an explicit 'prefer X over Y' routing statement, but the trigger-vs-data distinction gives solid guidance.

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