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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and closed-world, so the safety profile is covered. The description's only added behavior context is that the response is exactly one row containing provenance, review, vendor, and receipt sections, which is useful but thinly expressed.

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?

It is short with no wasted words and front-loads the most important fact (one row). However, the telegraphic fragment style crosses from concise into under-specified, since the listed nouns ("review", "provenance") are not self-explanatory.

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 simple one-param read tool with rich annotations this could be nearly complete, but there is no output schema, so the description must explain what comes back — and a four-word fragment naming cryptic sections does not convey the return structure, ordering, or failure modes (e.g., unknown transaction id).

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 required parameter at 100% schema description coverage (the schema even gives the format example "T-0012"), the schema carries parameter meaning. The description adds nothing about the transaction_id or how invalid ids behave, so 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?

"One row" implies a single-record fetch, and the field list (provenance, review, vendor, receipt) hints at the resource shape, but the description is a noun-phrase fragment with no verb and no explicit statement that this retrieves a transaction by id. It does not differentiate itself from neighbors like purch_get_bill, purch_get_receipt, or the list tool purch_transactions.

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?

There is no indication of when to call this versus purch_transactions (list) or the sibling single-record getters (purch_get_bill, purch_get_receipt), nor any prerequisite such as needing an existing transaction id. The agent must infer usage from the tool name alone.

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