mercury_list_credit_transactions

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

Annotations already declare readOnlyHint=true, aligning with the listing nature. The description adds behavioral context that pending items are card authorisations that may be reversed, which is beyond the annotations and schema.

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?

The description is concise with clear sections (purpose, use when, do not use, returns). It is front-loaded with the core purpose and uses minimal but informative sentences.

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?

Given the tool is a list operation with a rich schema and annotations, the description covers the use case, sibling differentiation, and return format. Even without an output schema, the sample return structure completes the picture.

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%, so parameters are well-documented. The description adds value by explaining the `status` filter meaning and providing a sample return structure, which aids understanding 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?

The description clearly states that the tool lists transactions on a Mercury IO Credit card account, including pending authorisations. It explicitly distinguishes from the sibling tool `mercury_list_transactions` by specifying credit vs. deposit account 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?

The description provides explicit 'USE WHEN' and 'DO NOT USE' guidance, specifying auditing, reconciliation, and building card-level views. It names the alternative tool `mercury_list_transactions` for deposit accounts and advises filtering by `status: 'sent'` for posted transactions only.

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