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

Annotations already communicate readOnlyHint, openWorldHint, idempotentHint, and non-destructiveness. The description adds valuable context beyond those hints: the backing data source (servicios.ine.es / INE Tempus3 API), that no authentication is required, and the exact fields returned. It does not address pagination or result size, but those are not critical for a metadata-list tool with an output schema.

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 three compact sentences with no filler. The main action and required parameter are front-loaded, and the data-source and no-auth details are included as a single efficient trailing sentence. Every sentence contributes operational information.

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 low parameter count, rich annotations, and presence of an output schema, the description is largely complete: it names upstream dependency (ine-spain.operations), downstream usage, return fields, and API source. It loses a point because it references 'ine-spain.table_data' while the available sibling is 'ine-spain.series.table_data', which could slightly mislead an agent navigating the tool list.

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%, so the schema already documents both operation_code and lang, including the valid enum values. The description reinforces the meaning of operation_code with examples and upstream context, which is helpful, but it adds no meaning beyond the schema for lang or parameter syntax. Baseline 3 is appropriate.

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 uses a specific verb ('List'), names the resource ('published data tables'), and scopes it to a Spanish statistical operation identified by operation_code. The examples ('IPC', 'EPA') and the explicit return fields (table_id, name, covered period) make the tool's purpose unmistakable, and it is clearly distinguished from sibling tools that return series data or operation lists.

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 usage context by saying operation_code comes from ine-spain.operations and that the returned tables are intended for ine-spain.table_data, establishing a pipeline. It stops short of explicitly stating when not to use this tool versus related alternatives such as ine-spain.series.data, so it earns a 4 rather than a 5.

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