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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false. The description adds genuinely useful behavioral context beyond that: prices are in Colombian pesos, billing cycles vary by category, and the `cycle` field must be inspected before comparison. No contradiction with annotations.

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 front-loaded with the main purpose and then detailed category bullets, all of which earn their place. The odd '-lang-customline0060-' placeholder is a minor blemish, but overall the structure is scannable and efficient.

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 search tool with no required parameters, an output schema, and strong annotations, the description covers the important semantics: category meanings, filter dimensions, currency, and billing-cycle caveat. It is complete enough for an agent to call the tool correctly; explicit sibling routing is the main missing piece.

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 description coverage, the description carries the parameter-meaning burden. It maps 'categoría' to the category parameter, 'presupuesto' to min/max_price, and 'recursos mínimos' to min_vcpu/min_ram_gb/min_disk_gb. It also provides the actual category values, which the schema omits. It does not explicitly discuss `limit`, but that parameter is self-explanatory.

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 opens with a concrete action and resource: 'Busca planes por categoría, presupuesto y recursos mínimos.' It specifies the exact search dimensions and then enumerates the meaningful categories, making its purpose unmistakable even without reading the schema.

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 gives clear contextual guidance for choosing categories and for interpreting prices, especially the warning to check the `cycle` field before comparing plans. It does not explicitly name sibling tools as alternatives, so it stops short of full when/when-not guidance, but the context is strong.

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