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

Annotations already cover read-only, idempotent, non-destructive and closed-world, so the description needn't repeat them; instead it adds genuinely new behavior: what is returned (endpoint, schema, example, x402 payment steps) and what is explicitly NOT done (no execution, no payment authorization). It does not mention caching or what happens with an invalid name, but the side-effect profile is clear.

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 sentences, zero filler, with the value proposition front-loaded and the negative constraint in the trailing clause where it belongs.

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 read-only lookup with no output schema and a fully documented single parameter, the description covers the content of the response and the no-side-effect guarantee. Minor gap: nothing about failure modes if the service name is unknown or unlisted.

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?

One parameter at 100% schema coverage, and the schema already explains it must be the exact name from via_list_services. The description adds only that the name identifies a single service. Baseline 3 given the schema does the heavy lifting.

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 (get) and resource (integration instructions for one VIA HTTP service) and enumerates the payload contents: exact endpoint, JSON input schema, example, x402 payment steps. The closing clause 'Does not execute the service or authorize payment' cleanly separates it from execution-oriented siblings like via_one_call.

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 negation clause implies the correct context (use this to learn how to integrate, not to run a call), and the schema points the agent at via_list_services for valid names. It stops short of explicitly naming via_one_call as the alternative for actual execution, so the routing is inferable rather than spelled out.

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