Inxmail MCP

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

With no annotations provided, the description carries the full burden and successfully discloses key traits: returns 'paginated HAL+JSON' format and declares 'Read-only' status. It also clarifies what error types are included vs excluded, though it omits rate limits or specific permission requirements.

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?

Every sentence serves a distinct purpose: definition, scope inclusion/exclusion, use case, related workflow tools, return format, and safety property. Well-structured and front-loaded without redundancy.

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?

Despite lacking an output schema, the description compensates by disclosing the return format (paginated HAL+JSON) and read-only nature. Given the tool's limited complexity (2 optional pagination params), the description provides sufficient context for invocation, though explicit auth requirements would improve it to a 5.

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 100% (size and page are fully documented with defaults and limits). The description adds no explicit parameter guidance, which aligns with the baseline score of 3 when schema coverage is high (>80%).

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 opens with the specific action and resource ('List system error log entries from Inxmail') and explicitly distinguishes from sibling tools by clarifying the scope includes 'API failures, rendering issues, and processing problems — not bounce/delivery errors (use list_bounces for those)'.

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 when-to-use ('Use this to diagnose server-side issues'), when-not-to-use (bounce/delivery errors), and named alternatives ('use list_bounces', 'Use get_error_log for full details', 'mark_error_log_read to acknowledge it').

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