Inxmail MCP

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

No annotations provided, so description carries full disclosure burden. Successfully declares read-only status and default time range behavior (last 30 days). Explains aggregation into a single report. Minor gap: no mention of error handling, rate limits, or report size limits.

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?

Four sentences with zero waste. Front-loaded with purpose ('Full delivery diagnostic'), followed by data details, usage guidance, and defaults. Each sentence earns its place 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?

No output schema exists, but description compensates by detailing the report contents (aggregated metrics from multiple sources). Adequate for a 3-parameter diagnostic tool despite missing annotations. Slight gap: could clarify report format or pagination behavior.

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 coverage is 100% with default values documented, establishing baseline 3. Description adds value by explaining the holistic date range behavior ('if no date range is specified') and contextualizing that parameters bound all aggregated data types (sendings, bounces, etc.) rather than describing parameters in isolation.

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?

States specific action (delivery diagnostic) and resource (email address) clearly. Explicitly enumerates aggregated data types (block status, sendings, bounces, reactions) and distinguishes from siblings by stating it consolidates functionality of list_sendings, list_bounces, list_reactions, and check_email_blocked.

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 guidance ('primary tool for investigating delivery issues') and explicitly names four sibling tools that should not be called separately when using this one. Clear directive on tool selection vs alternatives.

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