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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the agent knows this is a safe read operation. The description adds valuable behavioral context: it does not move money, it returns one page of at most 1000 records, large pages are truncated, and it cannot filter on Line fields or use OR. This goes beyond the annotations and helps the agent set expectations about the tool's behavior.

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 well-structured and front-loaded with the core purpose. The first sentence states what the tool does, and the second clarifies the domain meaning. The criteria parameter description is long but dense with necessary operational details. It earns its place because it covers filtering syntax, limitations, and pagination in a compact form. Slightly verbose in the criteria section, but not wasteful.

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 a search tool with no output schema, the description covers the essential operational details: what records are searched, how to filter, pagination limits, and known limitations. It does not describe the return format or fields returned, but for a search tool with a generic criteria parameter, the description is sufficiently complete for an agent to invoke it correctly. The lack of an output schema is partially mitigated by the detailed criteria documentation.

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 both parameters. The description adds meaningful context about the criteria parameter: it explains the accepted formats (array of {field, value, operator}, simple object, or {criteria, asc|desc, limit, offset, count}), the operators, the ANDed filtering, the lack of OR, the case-sensitivity, and the list of filterable fields. This is substantial added value beyond the schema's generic description.

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 ('Search'), a specific resource ('credit card payment txn records in QuickBooks Online'), and clarifies the domain meaning ('An accounting record of a bank payment toward a credit card balance'). It also distinguishes itself from related tools by noting it does not move money, which helps an agent differentiate it from create/update/delete credit card payment tools.

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 provides clear context for when to use the tool: searching credit card payment transaction records. It also gives practical guidance on filtering, pagination, and limitations (no OR, no Line fields, case-sensitive fields, one page of at most 1000 records). It does not explicitly name sibling alternatives like get_credit_card_payment_txn or create_credit_card_payment_txn, but the context is strong enough for an agent to infer when to use this search tool.

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