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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered without the description. The only additional context is that the record is returned 'in full' with the bank-supplied description and reference, which is modest added value since an output schema exists.

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?

A single front-loaded sentence, no filler, and the scoping ('One transaction in full') precedes the id provenance. Every clause earns its place.

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 single-parameter read tool with a full output schema and complete annotations, the description supplies what an agent needs to call it correctly. The minor gap is the absence of pagination/return-shape notes, which the output schema largely covers.

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% and there is only one parameter, so the schema already documents transaction-id. The description adds a small amount by noting find_merchant as a second id source that the schema omits, but otherwise duplicates the schema. Baseline 3 is appropriate.

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 uses a specific verb/resource pairing ('One transaction in full') and contrasts the single-record scope with the list-oriented siblings (list_transactions, find_merchant). An agent can tell it apart from list_transactions. It stops short of a fully explicit 'retrieve a single record' phrasing but the intent is unambiguous.

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 documents where the id comes from ('returned from list_transactions or find_merchant'), which is a genuine workflow hint, but never states when to prefer this tool over alternatives like export_transactions_csv or find_merchant directly. Usage is implied rather than guided.

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