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

Annotations already declare readOnly, openWorld, idempotent, and non-destructive behavior. The description adds useful context beyond those annotations: prices are current (MXN, IVA included) and no key is required, which helps the agent understand authentication and data semantics. It does not contradict the 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 extremely concise, with only two short clauses, and both carry meaningful information: the price table's nature/content and the lack of an authentication key. Every word earns its place, and the most important detail is front-loaded.

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 zero-parameter, read-only tool with rich annotations, the description covers what an agent needs: the data is a current price table in MXN with IVA included, and no key is required. No output schema exists, but the phrase 'tabla de precios' sufficiently indicates the return shape for this simple case.

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 input schema has zero parameters and schema description coverage is effectively 100%, so the baseline of 4 applies. The description does not need to explain parameters, and it correctly avoids fabricating any.

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 states the resource clearly: a current price table in MXN including IVA. It lacks an explicit verb like 'returns' or 'queries', but the tool name 'consultar_precios' supplies that action, and the scope is distinct from sibling tools. It is not vague, though it does not explicitly differentiate from 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 gives no guidance on when to use this tool versus any sibling, and it does not mention exclusions or alternatives. 'No requiere llave' is a useful prerequisite about authentication, but it is not a usage condition or comparison against other tools.

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