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

Annotations already declare destructiveHint=true and idempotentHint=true, and the description adds critical context: the operation is irreversible and requires explicit customer confirmation before calling. It also discloses the auth requirement (customer_grant or signed-in customer). This goes beyond the 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?

Two sentences, front-loaded with the core action and irreversibility warning. Every sentence earns its place; no filler.

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 destructive, irreversible mutation with no output schema, the description covers the critical behavioral context (irreversibility, confirmation requirement, auth prerequisites). It doesn't describe the return value, but the absence of an output schema lowers the bar. Minor gap: no mention of what happens to related resources (e.g., payments), but the core is covered.

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 only 20%, so the description must compensate. It mentions idempotency_key and customer_grant in the context of requirements, but doesn't explain booking_reference, reason, or session_id beyond their schema names. The description adds some meaning but leaves most parameters to be inferred from names.

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 ('Cancels') and resource ('the verified customer's booking'), and the title 'Anuluj rezerwację' (Polish for 'Cancel booking') reinforces it. It clearly distinguishes from siblings like reschedule_booking and create_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 states when to use: cancels the verified customer's booking. It also gives clear prerequisites: requires customer_grant or a signed-in customer and an idempotency_key. It doesn't name alternatives, but the context is clear enough for an agent to know when to invoke it.

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