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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety and locality are covered. The description adds conceptual context (a template QBO uses to create transactions on schedule or on request) but says nothing about permission requirements, error behavior for a missing Id, or response shape. With annotations carrying the behavioral burden, this is adequate but not rich.

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?

Two compact sentences, with the verb and resource front-loaded and the conceptual gloss trailing. The second sentence is arguably optional context, which keeps it just short of a 5.

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 two-parameter read-only getter with no output schema, the description plus annotations and full schema coverage give an agent everything needed to invoke it correctly. Only the return-shape and missing-Id behavior remain unspecified, which is a minor gap given the tool's simplicity.

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% for both id and company, so the schema already documents the parameters fully. The description only restates that lookup is by Id and adds no format, realm-id, or scoping detail beyond what the schema provides. Baseline 3 applies.

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 and resource ('Get a single recurring transaction ... by Id') and names the system (QuickBooks Online). The second sentence adds a clear conceptual definition of the resource as a template used to create transactions on a schedule, which separates it from create_recurring_transaction and search_recurring_transactions without needing their schemas.

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?

'when no search or write answer already holds it' tells the agent this is the fallback direct-fetch path rather than the search path, which is real routing guidance. It stops short of naming search_recurring_transactions explicitly or stating exclusions, so it is clear context without a fully spelled-out when-not clause.

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