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

Annotations declare write/side-effecting, open-world, non-idempotent behavior, but the description adds the crucial concrete disclosure that an email is actually sent to the customer's address — a real external side effect an agent must anticipate. It stops short of saying whether repeated calls send repeated emails or whether the code expires.

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 trigger clause is front-loaded, the mechanism follows in one compact sentence, and the two example payloads efficiently convey the optional-parameter shape. No filler sentences.

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?

An output schema exists, so the description needn't explain return values, and it correctly focuses on the flow it initiates. The only material gaps are the unexplained market parameter and the absence of a pointer to the verification step that consumes management_id.

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?

With 0% schema description coverage, the description must carry the load: it explains that email is the booking's address the code goes to, and that reservation_number is optional and narrows the unlock scope to one reservation versus every reservation on that email. The market parameter is not mentioned at all, leaving one of three parameters undocumented in both schema and 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 action (starts reservation management) and the concrete mechanism: it emails a 6-digit code to the booking's email address and returns a management_id. This clearly distinguishes it from siblings like cancel_reservation or list_my_reservations, which operate on an already-established session.

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?

"Use when the user wants to see, cancel or extend their reservations" gives an explicit trigger condition, and the description explains the two modes (with vs. without reservation_number). It does not name the follow-up tool (verify_reservation_management / confirm_reservation_code) or any alternative entry point, so it stops short of full routing guidance.

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