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

The annotations only declare readOnlyHint=false, so the description must carry most of the behavioral burden. For a mutation that registers personal data, it does not disclose consent or privacy handling, idempotency, whether a pass can be claimed more than once, or what side effects occur after activation.

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 description is a single, front-loaded sentence with no filler. The core action and benefits appear before the registration details.

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?

There is no output schema and the annotations are minimal, so the description should do more for a mutation that collects PII. It states what the pass unlocks but leaves out important context such as consent, data handling, repeat-claim behavior, and how this differs from redeeming a trip pass code.

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 schema already documents all six parameters thoroughly. The description mentions mobile number, email, and trip dates but omits name, partySize, and wantsTravelQuote, and it implies email and trip dates are part of registration even though only phone is required.

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 uses a specific verb and resource: activate a 100% Free MouseEdge Starter Pass, and lists concrete benefits (3 concurrent watches and AI trip planning). It is clear what the tool does, but it does not distinguish it from nearby siblings such as redeem_trip_pass_code or compare_disney_apps_and_passes.

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 explains the mechanism (registering mobile, email, and trip dates) but gives no guidance on when to use this tool versus alternatives. It does not mention prerequisites, exclusions, eligibility, or how it differs from redeem_trip_pass_code.

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