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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds genuinely useful behavior beyond annotations: an explicit pricing model ($0.002 USDC per successful call via x402 across Base/Solana/Arc) and the note that failed calls are not charged. It does not detail pagination or response shape, but the output schema exists for that.

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?

Three compact sentences, each earning its place: identity/scope, the exclusion plus next step, and pricing. The key scoping facts are front-loaded.

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 an output schema present, the description needn't explain return format, and it covers source, ordering, field contents, exclusions, and payment terms. Only minor gaps (no mention of rate limits or caching freshness) remain for a single-param read tool.

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 optional parameter with 100% schema description coverage, so the schema already documents the 1-50 range and default of 5. The description adds no further parameter meaning, so 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+resource: the EU Safety Gate (RAPEX) weekly product-safety report index sourced from the European Commission's public XML list. It further specifies what each entry returns (reference, publication date, week, alerts link) and ordering (newest first), which no sibling tool covers.

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?

Explicitly tells the agent the boundary: 'Product-level details are not included; open the returned link for them.' That is clear guidance on when this tool suffices and what to do next. It lacks an in-catalog alternative reference, but none of the siblings are RAPEX equivalents.

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