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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so the safe read-only profile is fully covered by structured data. The description adds only that the result is a "complete" catalog covering two rail types and pricing, without describing the return shape, entry fields, or how pricing is presented. With annotations carrying the behavioral load, this is an adequate rather than rich addition.

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?

Two short sentences, both front-loaded: the capability statement first, then the routing rule. Every clause earns its place, with no restatement of the title or schema.

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?

For a zero-argument, read-only catalog with no output schema, the description supplies what an agent needs: what the catalog enumerates and why to call it before other tools. It stops short of describing the catalog's entry structure or how prices are formatted, a small gap given no output schema exists.

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?

The tool takes zero parameters, so there is nothing for the description to disambiguate and the baseline of 4 applies. The description correctly implies a single unfiltered call rather than a filtered query, which matches the empty schema.

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 ("Return") and a specific resource ("complete catalog of Orivale x402 Base/Solana USDC APIs and 8 Apify Store Pay-Per-Event cloud scrapers"), which tells the agent exactly what comes back and the catalog's scope. It also implicitly distinguishes itself from the scraping siblings by naming the two rail families it enumerates.

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 an explicit positive directive ("Call first for capability/price discovery") and an explicit exclusion ("do not call to scrape a URL"), which routes the agent away from the scraper siblings such as orivale_clean_markdown or orivale_youtube_transcript_hooks. Nothing about when to invoke it 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.