mailing_lists_catalog

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

The description discloses the behavior: it reads from a JSON configuration, lists presets, and returns specific fields or an error if unset/invalid. Since no annotations are provided, the description carries full burden, and it adequately explains the return structure and error conditions.

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, with each sentence adding value. It front-loads the purpose, then gives usage context, then outlines the return format. 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 no parameters and no annotations, the description is complete. It explains what the tool returns, how to use it (with reference to sibling tool), and potential errors. It fits well within the context of sibling tools.

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 tool has zero parameters, and the input schema is an empty object. The description adds value by explaining the return fields and possible error, which is sufficient given no parameters need explanation.

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: 'List named mailing-list presets from EMAIL_MCP_MAILING_LISTS (JSON).' It uses a specific verb ('List') and resource ('mailing-list presets'), and distinguishes itself from the sibling tool 'mailing_list_latest' by mentioning it returns configuration that can be used with that tool.

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 guidance on when to use this tool: 'Configure labels/folders once ... then use mailing_list_latest(id).' This implies the catalog should be used first to list presets before using the latest tool. However, it does not explicitly state when not to use it or mention alternatives.

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