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

With no annotations, the description carries the behavioral burden and usefully discloses the paid $0.005 USDC per-call x402 mechanism and the free 3-row sample preview. It does not cover rate limits, error behavior, or return shape, but the cost and preview behavior are significant additions.

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?

The description is front-loaded with the resource name and packed with useful route, parameter, payment, and sample information without filler. Every sentence contributes directly to correct invocation.

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 route-based directory tool with no annotations and no output schema, the description covers purpose, routes, query parameters, payment, and free preview adequately. It could say more about return format, but given the schema coverage it is sufficiently 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 100%, so the baseline is 3, but the description adds meaning by enumerating /search query parameters (q, category, country, limit, offset) and clarifying the /categories and /{wikidata} routes. This goes beyond what the route schema alone 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?

The description clearly identifies the resource as an 'Online Platforms Directory' and lists the available routes (/search, /categories, /{wikidata}). It distinguishes the domain from sibling tools like airports or colors, though it does not explicitly contrast behavior with those siblings.

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?

It provides concrete use cases (market research, competitor maps, onboarding flows, AI agents) and lists the routes, which tells an agent when this tool is relevant. It does not give explicit when-not-to-use guidance or name a preferred alternative for overlapping needs.

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