mercury_get_transaction

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

Annotations only say readOnly/openWorld; the description adds real behavioral detail beyond that, notably that attachment URLs are stripped from the response and must be fetched via mercury_get_transaction_attachment. That is exactly the kind of hidden-surprise disclosure annotations cannot carry.

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?

Front-loaded verb+resource in the first sentence, then clearly labeled USE WHEN / DO NOT USE / RETURNS blocks. No filler; even the return shape sample earns its place by implying the attachments structure.

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?

There is no output schema, but the description supplies the return shape and explicitly flags the one omitted field (attachment URLs) with the sibling to call instead. Nothing an agent needs to invoke or interpret this correctly is missing.

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% and both parameters are UUIDs documented in the schema, so the baseline is 3. The description only hints at provenance ('typically from mercury_list_transactions') without adding format or constraint detail beyond the schema.

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 ('Retrieve a specific transaction by ID') plus the scope ('Mercury deposit account'), which lets an agent distinguish it from list_transactions, list_credit_transactions, and get_transaction_attachment without opening a schema.

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?

Explicit USE WHEN section names the trigger condition (ID already known, typically from mercury_list_transactions) and explains why it beats relisting. DO NOT USE section names both alternatives and when to prefer each, including the client-side filter workaround for IO Credit transactions.

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