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

Annotations already declare this as read-only, idempotent, and non-destructive. The description adds useful behavioral context beyond that: prices are in COP, billing cycles vary by category, `price` is the main period, and `prices` includes all selling periods with installation costs.

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 well-structured: a concise purpose statement, a bulleted category list, then a focused pricing caveat. It is somewhat long, but the category detail is genuinely useful because the schema provides no enum values.

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?

Given the output schema and safety annotations, the description covers the key domain semantics: valid categories, currencies, cycles, and price fields. Minor gaps remain around price-filter interaction and pagination through `limit`, but they are not severe enough to make the tool hard to use.

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?

With 0% schema coverage, the description compensates by enumerating category values and explaining price currency and cycle behavior. However, it leaves some parameter semantics unclear, such as how `min_price`/`max_price` relate to `price` versus `prices`, and it does not discuss `limit` or resource-unit details.

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 action and scope: searching plans by category, budget, and minimum resources. It does not explicitly distinguish this from siblings such as get_product or compare_products, though the filtering language strongly implies the difference.

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 clear operational context: use this to find plans by category, budget, and resource filters, and it warns to inspect `cycle` before comparing plans. It lacks explicit when-not-to-use guidance or alternative routing to siblings like get_product or compare_products.

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