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

Beyond the readOnly/idempotent annotations, it discloses that authentication is required, that only the caller's own data is returned, and explicitly what is never exposed (card numbers, payment-method identifiers, checkout links). It also documents cursor pagination, newest-first ordering, and that filters AND together.

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?

Front-loaded with the safety/auth statement and organized into terse clauses; dense but nearly every clause carries information. Slightly packed into one long paragraph, 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?

With annotations covering safety and an output schema covering return values, the description fills the remaining gaps: auth requirement, data exposure limits, scoping defaults, filter combination, and pagination. Nothing needed to call it correctly is missing.

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Schema coverage is 100%, so the baseline is 3, but the description adds real meaning: all_schools is superseded by school_slug, student_id is limited to the caller's own students, and filters combine with AND. Cursor usage (pass returned nextCursor) is also explained behaviorally.

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 (list the caller's own wallet transaction history) and enumerates the returned fields, clearly distinguishing it from get_my_wallet_balance and the lunch/event list siblings.

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?

Gives concrete context: defaults to the active school, use all_schools for every school, use student_id to narrow to one student, and topUpUrl is for when the user asks to add funds. It does not explicitly say when to prefer this over get_my_wallet_balance, so not a full 5.

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