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

Annotations are empty, so the description bears the transparency burden. It discloses that the tool debits a transaction fee and explicitly warns to confirm before executing, which is meaningful behavioral context. But it does not mention reversibility, balance requirements, permission prerequisites, or failure behavior, leaving gaps for a financial mutation tool.

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 structured with clear @param sections and is mostly efficient, but the sentence 'Charges the account a transaction fee' is repeated verbatim, adding no new information. The confirmation instruction also appears once, but the duplication makes it less concise than it could be.

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 5-parameter financial mutation with no annotations, the description covers the core purpose, confirmation requirement, all parameters, and return type, while the output schema supplies return shape. However, it lacks guidance on when to use this tool versus sibling payment/account tools and omits side effects or prerequisites beyond auth tokens, so some context is still 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?

The description thoroughly documents every parameter via @param lines, adding meaning beyond the bare schema. It clarifies that api_key is application-allocated, token comes from /access/login, account_fk is a database ID (not an address) and may not be 0, amount is the charge amount, and note is optional. Since schema coverage is 0%, this description is essential and highly effective.

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 the tool's action with a specific verb ('Charges') and resource ('the account') and the nature of the charge ('a transaction fee'). However, it does not explicitly distinguish this from sibling tools like account_charge or account_send, so it stops short of full differentiation.

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 one concrete usage instruction: 'Confirm (yes/no) before executing,' which tells the agent to get user confirmation before calling the tool. However, it gives no guidance on when to prefer this tool over alternatives like account_charge or account_buy, and no exclusion conditions are mentioned.

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