open_account

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It reveals two important behaviors: all accounts post in the ledger currency (single-currency constraint) and accounts may not go negative unless allow_negative is set, framing overdraft as an intentional policy. This provides meaningful context beyond the 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 two sentences, front-loaded with the primary action, and every sentence earns its place. It is concise without sacrificing key behavioral constraints.

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 no annotations, no output schema, and only three simple parameters, the description covers the essential behavioral constraints (single currency, negative balance policy). It does not mention error cases like duplicate account IDs, but for a simple creation tool, it is reasonably complete.

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%, so baseline is 3. The description does not add meaningful parameter-level detail beyond what the schema already explains; it only restates the allow_negative policy in prose, which is already captured in the schema description. No new syntax or format guidance is provided.

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 function with a specific verb and resource: 'Open a ledger account.' It also adds context about ledger currency and negative balance policy, which distinguishes it from sibling tools like get_balance, post_entry, and list_accounts.

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 usage is implied rather than explicit; the description implies this tool is for creating accounts but does not explicitly state when to use it versus alternatives. No exclusions or alternative tool references are provided, so guidance is minimal.

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