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

Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=false), so the bar is lower, and the description still adds meaningful substance: prices are quoted in USD per month, signup links are included, and Enterprise is handled via a sales contact rather than self-serve. It does not mention caching/refresh behavior or whether pricing data is static, but the added context is real.

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 sentence, front-loaded with the primary payload (plans and prices), then progressively adding secondary detail. No filler, no restatement of the tool name or 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 carries the full burden of describing the return payload and does so exhaustively — prices, limits, signup links, sales contact, features, and their help articles. An agent knows exactly what it will receive before calling.

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% and the single enum parameter (billing_cycle) is documented there, including 'Omit to get both.' The description adds no syntax or behavior beyond that; if anything, its 'prices in USD per month' phrasing slightly understates the yearly option the schema exposes. Baseline 3 applies.

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 enumerates the exact resource payload: plans, USD monthly prices, plan limits, signup links, Enterprise sales contact, and per-plan features with linked help articles. This is clearly distinguishable from the sibling tools get_article and search_docs, which retrieve documentation rather than structured pricing.

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?

Usage is only implied: the tool's subject matter (pricing/plans) makes it obvious when to reach for it instead of get_article or search_docs, but the description never states when to use it, when not to, or names an alternative. No prerequisites or exclusions are given.

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