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

Annotations only declare readOnlyHint=true. The description earns extra credit by disclosing the return shape (line items, currencies, metadata), which is meaningful given there is no output schema, and by mapping to the underlying REST call GET /tax/transactions/{transaction_id}. It omits auth requirements, rate limits, and error 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?

Three short sentences, front-loaded with the operation and its identifier, then the return contents. The final REST-endpoint sentence is largely redundant with the tool name but serves as a useful API mapping and takes little space.

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 one-parameter read tool with no output schema, the description covers what is fetched and what comes back (line items, currencies, metadata). Nothing essential is missing for correct invocation, though not-found/error behavior is unstated.

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 a single parameter at 100% schema description coverage, the schema already documents transaction_id and its tr_... format. The description repeats the id format but adds no new semantics, so the 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 recorded transaction by its Numeral id'), which clearly separates it from numeral_create_transaction and numeral_list_transaction_refunds. It does not explicitly name or distinguish itself from any sibling, which keeps it just short of a 5.

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?

Usage is implied: the tool is for the case where you already hold a transaction id. There is no statement of when to prefer this over the list/refund siblings, no preconditions, and no exclusions, so it stays at the minimum viable level.

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