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

Annotations already declare this as a safe, read-only, idempotent operation. The description adds useful behavioral context beyond them: results are newest first, pagination uses limit and offset, and the call is free. It does not discuss auth or rate limits, but that is minor here.

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?

Three short sentences, with the main purpose front-loaded and alternatives appended efficiently. No filler or repetition.

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?

Given a simple read-only list tool with full schema coverage, annotations, and an output schema, the description supplies the key context: scope, ordering, pagination, cost, and sibling routing. Complete enough for correct invocation.

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 all three parameters are already documented in the schema. The description mentions pagination via limit and offset and wallet scoping, but adds little detail beyond what the schema provides.

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 resource and scope: every receipt the wallet has paid for, ordered newest first, with per-tool counts and total charged. It is immediately distinguishable from receipt_lookup and watch_list by naming both alternatives.

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?

Clearly indicates this tool is for full receipt history and routes single-receipt lookups to receipt_lookup and URL watches to watch_list. It lacks an explicit when-not condition, but the alternatives establish the boundary well.

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