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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the bar is lower; the description still adds value by naming the currency (USD) and the source of truth ('live plan catalog'), plus redirecting purchase intent off-tool. It doesn't say whether prices/plans can change between calls or how stale the catalog might be.

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?

A single tight sentence (plus one clause) that front-loads the resource, currency, and returned fields. No filler or restatement of the title.

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 no output schema, the description usefully enumerates the return payload (monthly price, one-time setup fee, included minutes). It could be slightly stronger by stating whether the list is stable or frequently updated, but for a zero-arg read tool this is close to 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?

The tool takes zero parameters, so the baseline is 4; there is nothing for the description to disambiguate. The description correctly implies the call is argument-free and unconditional.

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 resource and scope: current monthly plans from VoiceDesk AI's live plan catalog, in USD, with three enumerated returned fields. It is clearly distinguishable from get_services by the pricing/plan framing, but never names that sibling explicitly.

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 note that 'purchases happen only on voicedeskai.org by the business owner' sets one useful boundary (this tool is informational, not a purchase path). However, there is no guidance on when to prefer this over get_services or how it fits into an onboarding flow.

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