mercury_list_customers

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

Annotations already declare readOnlyHint=true and openWorldHint=true. The description adds cursor-based pagination details ('Use startAfter / endBefore for paging beyond the limit') and return format, enhancing transparency beyond 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?

The description is concise (5 sentences) with clear sections: purpose, USE WHEN, DO NOT USE, RETURNS. Front-loaded with purpose, no redundant information.

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's simplicity (list with pagination), annotations, and schema, the description covers usage context, pagination, and return structure. Output schema is not provided, but description specifies return format. Complete for a list endpoint.

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 75%, with parameter descriptions for limit, startAfter, and endBefore. The description adds context on how to use pagination cursors ('Use startAfter / endBefore for paging'), but does not document the 'order' parameter, which is not described in schema either.

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 states 'List Accounts Receivable customers, with cursor-based pagination.' It provides a specific verb ('list'), resource ('AR customers'), and mentions pagination. It distinguishes from siblings like 'mercury_list_recipients' and 'mercury_get_customer'.

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?

Explicitly states when to use ('enumerating AR customers before creating an invoice...or for a customer-level audit'), when not to use ('DO NOT USE: for payment recipients'), and provides alternatives ('mercury_list_recipients', 'mercury_get_customer').

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