Email SMTP/IMAP MCP Server

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 mentions listing folders and organizing emails, but fails to disclose critical traits such as whether this requires authentication, rate limits, or how the output is structured (e.g., pagination, error handling). This leaves significant gaps for an agent to understand the tool's behavior.

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 appropriately sized with two sentences that are front-loaded and efficient. The first sentence states the purpose clearly, and the second adds context without redundancy, making it easy to parse with minimal waste.

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 low complexity (2 parameters, no output schema, no annotations), the description is somewhat complete but lacks depth. It covers the basic purpose and usage but omits behavioral details like authentication needs or output format, which are important for a tool with no annotations or output schema to rely on.

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 input schema has 100% description coverage, clearly documenting both parameters ('account_name' and 'include_counts'). The description adds no additional parameter semantics beyond what the schema provides, so it meets the baseline score of 3 without adding or detracting value.

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 with a specific verb ('List') and resource ('email folders/labels'), making it easy to understand what it does. However, it doesn't explicitly differentiate from sibling tools like 'emails_find' or 'emails_modify', which prevents a perfect score.

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 implied usage guidance by mentioning 'to see your folder structure and organize emails', which suggests when this tool might be useful. However, it lacks explicit guidance on when to use this versus alternatives like 'emails_find' for searching emails, leaving room for ambiguity.

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