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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds value on top by describing that results are newest-first by default, what fields come back, and how q/merchant/date filters narrow the search. It doesn't contradict any annotation and gives behavioral detail beyond the schema.

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 compact, front-loaded with the object type and output fields, then the filters, then the use case. It lists several output fields, but since no output schema exists, that enumeration earns its place. It is dense but not bloated.

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 10 parameters, no output schema, and only read-only annotations, the description covers the core return shape and filter semantics. It doesn't explain cursor/pagination bounds in prose, but the schema already handles those descriptions, and the remaining context is adequate 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?

With 100% schema description coverage, the baseline is 3. The description adds extra semantics: q examples ('manzana', 'papel higiénico'), the meaning of merchant as narrowing to one shop, and the date bounds for purchase day. This enriches the parameter descriptions rather than merely repeating them.

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 states a specific verb and resource: search receipt line items, and it lists exactly what kind of data is returned (description, product name, brand, quantity, prices). It distinguishes itself from sibling tools like list_receipts or summarize_receipt_items by focusing on line-item search and filtering, and the use-case quote clarifies its place.

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?

It explicitly gives usage context: answer 'what did I pay for X on that receipt' or list what was bought somewhere. It does not name specific alternatives to avoid or provide a when-not clause, but the intended triggers are clear enough for an agent to select it appropriately.

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