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

Adds substantial context beyond the annotations: it returns a Stripe Checkout URL that the purchaser must visit, the student receives a separate activation email, and pricing varies by campus/term with priceCents echoed. It does not explain why destructiveHint is set or any auth/permission requirements, keeping it short of a 5.

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?

Four sentences, front-loaded with the action and scope, each contributing distinct information (campuses, purchaser/student roles, checkout flow, pricing source). Slightly dense but 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 an 11-parameter purchase tool with no output schema, it covers the end-to-end flow and what is returned (checkout URL, priceCents echo) plus the list_campuses dependency. Minor gaps remain around failure/retry behavior and the significance of the destructive annotation.

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 100% schema coverage the baseline is 3, but the description adds meaningful meaning by explaining the two-party model (purchaser vs student) and the list_campuses dependency for campus/term IDs, which helps an agent map its inputs correctly.

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 ('Buy a Fold Semester Pass') and immediately scopes it to four named campuses and a college-student use case. It clearly distinguishes itself from siblings like get_semester_pass and activate_semester_pass by describing the purchase-and-checkout action.

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 routes the agent to list_campuses for campusId, termId, and pricing, and clarifies the purchaser-vs-student split. However, it never states when NOT to use this tool or how it differs from adjacent actions such as apply_promo_code or book_my_pickup, so it lacks explicit exclusions.

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