mercury_list_accounts

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

Annotations readOnlyHint:true and openWorldHint:true indicate safe read operation and broad scope. Description adds context: returns account details with fields id, name, kind, status, balances, accountNumber, routingNumber, etc., and implies it lists all accounts (no parameters). No contradiction with annotations.

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?

Concise, with clear section headers (USE WHEN, DO NOT USE, RETURNS). Every sentence adds value—no redundant or fluff content.

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?

No output schema, but description fully specifies the return shape with example fields. With zero parameters, all necessary context is covered: purpose, usage, and output format.

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?

Input schema has zero parameters (100% coverage), so description need not explain parameters. Baseline is 4 per guidelines; description adds no extra param info but reinforces that the tool lists all accounts without filters, which is helpful.

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?

Explicitly states it lists deposit bank accounts (checking, savings, treasury) in Mercury workspace, uses specific verb 'list' and resource, and distinguishes from sibling tools by naming credit accounts and single-account endpoint.

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?

Provides explicit 'USE WHEN' for enumerating before drilling into transactions/balances, and 'DO NOT USE' for IO Credit card accounts (pointing to mercury_list_credit_accounts) or when account ID is known (prefer mercury_get_account). Clear guidance with alternatives.

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