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

Annotations already establish read-only, idempotent, non-destructive, and closed-world behavior. The description adds meaningful context beyond annotations: it enumerates the returned pricing and terms fields, states the source, and includes a checked date for data freshness.

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 information-dense and front-loads the returned content before input examples and provenance. It is a long run-on enumeration, but every clause contributes relevant scope rather than filler.

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 one parameter, no output schema, and strong read-only annotations, the description is largely complete because it explains the return content, accepted input style, and data provenance. It could add guidance on ambiguous vendor names or how to discover valid ids, but the essential calling context is present.

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 schema already documents the single 'vendor' parameter at 100% coverage. The description adds concrete examples such as 'Ruby', 'Smith.ai', 'Rosie', and 'RingCentral', making it clearer that either an id or a name is accepted.

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 defines the resource as one vendor's published pricing, overage, volume costs, billing terms and integrations, with URL and read date. It distinguishes the single-vendor scope from broader sibling tools by saying 'One vendor's,' though it does not explicitly name the alternatives.

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 description explains what can be retrieved but does not state when to use this tool versus siblings such as list_vendors or compare_at_volume. No explicit when-to-use, exclusions, or discovery guidance is provided.

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