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

Annotations already declare readOnly/idempotent/non-destructive, so safety is covered. The description adds real behavioral context beyond them: no reservation is made here, and days outside the Zaca+ Club advance window are surfaced as club_only, which is a data-semantics detail an agent could not infer from annotations or 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?

Three compact sentences, front-loaded on what the tool returns, with the booking/club_only caveats following. The inline definition of ludoteca is worth its length; there is minor redundancy between the title and opening phrase.

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-required-param, read-only listing tool with full schema coverage and complete annotations, the description covers purpose, scope, booking boundary and the club_only caveat. Return-value shape is not described and no output schema exists, but this is a minor gap for an availability listing.

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 date format, days range, store code/name and country enum are all already documented in the schema. The description's 'por tienda y día' is consistent with but not additive to those field definitions, so the baseline 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?

States a specific resource and scope: free table slots at Zacatrus store game libraries, broken down by store and day. The parenthetical explaining what the ludoteca is removes ambiguity, and the explicit 'Sin reservar nada' separates this read-only listing from the booking flow (the book_table sibling).

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?

Gives clear context: use this to see availability, and to book you must enter the website with an account (link in url) rather than use a tool. It also explains the club_only advance-booking window, which tells the agent how to interpret results for non-club customers. It does not name the book_table sibling directly for contrast, so it stops 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.