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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint. The description adds useful behavioral context beyond annotations: live data source, pagination size, ordering, the is_reconciled field, and a semantic distinction from statement lines. There is no contradiction with annotations.

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 front-loaded with the core listing behavior and pagination details, then sharpens context with a disambiguation and use cases. The final 'Routing' line partially repeats the earlier use-case sentence, but the duplication is minor and the whole description remains compact.

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 the simple parameter set and the presence of annotations, the description covers the essential invocation context: data source, pagination, ordering, row field, semantic scope, and intended use cases. With no output schema, mentioning is_reconciled helps, though a bit more about return shape would be ideal.

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 baseline is 3. The description does not add parameter-specific semantics beyond what the schema already documents. That is acceptable when the schema covers all parameters.

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: 'List LIVE bank transactions from the company's connected Xero ledger' with concrete details like 'paged, 100 per page, newest first'. It also prevents confusion by explicitly distinguishing these money documents from Xero Reconcile-tab statement lines. This is strong sibling differentiation without needing to name 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?

Clear usage context is provided: 'Use for current bank activity or verifying a payment hit the books' and the routing line 'use for current bank activity questions'. However, it does not explicitly state when not to use this tool or name alternative tools like search_transactions or list_xero_unreconciled.

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