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

Annotations already mark this as a non-readonly, non-idempotent, non-destructive write. The description adds real behavioral context beyond them: Zacatrus emails the confirmation with a QR, and the client must be authenticated. It stops short of saying what happens if a slot is already taken or whether a retry duplicates a booking.

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?

Five short sentences, each carrying distinct actionable content: prerequisite lookup, confirmation ask, phone rule, post-booking notification, auth requirement. No filler and the key prerequisite 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 mutation tool with no output schema, the description covers the outcome (confirmation email with QR), the auth requirement, and the ordering of operations. It leaves unstated what a failed or conflicting reservation looks like, but an agent has everything needed to invoke it correctly.

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, but the description adds cross-tool semantics: slot values must come from ludoteca_slots and the phone must be collected fresh for this reservation rather than reused. That is meaning beyond the schema's field-level prose.

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 verb+resource+scope: reserving a ludoteca table at a Zacatrus store for a customer. This clearly separates it from ludoteca_slots (which only lists availability), my_bookings, and cancel_booking.

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?

Explicitly prescribes the prerequisite step (search free slots with ludoteca_slots first), the confirmation flow (client must confirm store, day and slots), and the gating condition (client must be logged in). It also gives an exclusion-style rule: never assume or reuse a phone number from another booking.

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