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

With no annotations, the description carries the behavioral burden and clearly discloses that omitting location/city returns the country/global scope, and that only 'active' promotions are returned (implying a read-only operation). It does not delve into response format or pagination, but for a simple query this is sufficient.

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 two compact sentences, provided in both Spanish and English, with the key action and object front-loaded. It contains no filler and effectively communicates the tool's functionality and default behavior.

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 query with two optional parameters and no output schema, the description adequately covers input modes and the default scope. It could mention result ordering or limits, but those are minor gaps given the tool's simplicity and the parameter documentation in the schema.

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 schema already has 100% description coverage: 'Filter by city' and 'The USER's location (not the agent's)'. The tool description only restates the parameters ('by location {lat,lng} or city') without adding new semantic details, so the baseline score of 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?

The description clearly states it returns 'Active promotions from directory businesses' and explains the two filtering modes (location/city) with a country/global fallback. This specific verb+resource combination distinguishes it from sibling tools like ver_negocio (view business) and buscar_negocios (search businesses), which are about businesses rather than promotions.

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 implies when to use this tool: when you need promotions, optionally filtered by location or city, and it explains the no-filter fallback. However, it does not name alternative tools or provide explicit when-not-to-use guidance, which keeps it just short of a 5.

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