mmex_accounts_balance

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

No annotations are provided, so the description must fully disclose behavioral traits. While it correctly implies a read-only operation by saying 'Get', it fails to mention potential errors, authentication requirements, or the fact that it queries a database file. The env var fallback is noted, but overall transparency is minimal.

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 extremely concise: one sentence for purpose followed by a bullet-like Args list. Every sentence adds value. No extraneous information. The structure is clear and easy to parse.

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?

The tool has an output schema (indicated by context), so the description does not need to detail return values. However, it does not mention that the result is a numeric balance or any edge cases (e.g., account not found, zero balance). For a simple tool, this is adequate but leaves some ambiguity.

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 0%, so the description must compensate. It does so by listing each parameter with a brief explanation: account_id is 'The account ID', db_path and db_key have optionality and env var fallbacks. This adds meaning beyond the bare schema titles, but could be more detailed (e.g., data type constraints, valid ranges).

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 purpose: 'Get the balance of an account.' It uses a specific verb ('Get') and resource ('balance of an account'), distinguishing it from sibling tools like mmex_accounts_get (which retrieves full account details) and mmex_accounts_list (which lists 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 description does not provide any guidance on when to use this tool versus alternatives. It lacks statements about prerequisites, context, or when not to use it. The agent receives no assistance in deciding between this and other account-related tools.

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