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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false. The description adds valuable context beyond these: no auth required, the underlying API source (servicios.ine.es INE Tempus3 API), the default period behavior, and the per-series data volume. No contradictions 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?

Three sentences with no wasted words: the core action is front-loaded, followed by the capacity constraint, the alternative tool, and the data source. Every clause contributes to selection or invocation.

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?

The description covers purpose, usage context, alternative, auth requirements, and source. With an output schema present, return-value documentation isn't needed. The one gap is the slightly inaccurate tool reference ('ine-spain.tables' vs the actual sibling 'ine-spain.reference.tables'), which could briefly misroute an agent looking for the table-list tool. Otherwise complete.

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 baseline is 3. The description adds minimal parameter meaning beyond the schema: it reiterates the periods cap and default, and points to the source of table_id, but the schema already explains each parameter in comparable detail. The description doesn't need to compensate, so the 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 states a specific verb and resource: 'Get the most-recent data points (1-6 periods, default 1) for EVERY series in a table.' It explicitly distinguishes itself from the sibling ine-spain.series_data by contrasting per-table vs per-series scope. The only minor blemish is the reference to 'ine-spain.tables' when the sibling list shows 'ine-spain.reference.tables', but the core purpose is unambiguous.

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 an explicit alternative: 'use ine-spain.series_data for a longer single-series history.' It also explains the rationale for the periods cap ('Tables can bundle hundreds of series, so periods is capped tightly'), giving the agent clear decision criteria for when this tool is appropriate.

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