Inxmail MCP

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

No annotations provided, but description compensates well by declaring 'Read-only' status and return format 'paginated HAL+JSON'. Mentions pagination behavior. Could improve by mentioning rate limits or default behavior when no filters applied.

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 dense sentences with zero waste: scope definition, use case, alternatives guidance, and technical contract. Well front-loaded with the critical 'event-triggered only' constraint.

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?

Strong compensation for missing output schema by describing return type (HAL+JSON) and pagination. All 8 parameters documented in schema. Sibling differentiation is clear. Minor gap: doesn't describe what 'sending details' includes in the response.

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%, establishing baseline 3. Description maps parameters to concepts ('Filter by recipient email, event type...') but adds minimal semantic detail beyond schema descriptions. Does not clarify relationship between 'event' and 'eventId' parameters.

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?

Excellent specificity with 'List transactional email sendings' and clear scope delimitation '(event-triggered emails only, not mail relay)'. Explicitly distinguishes from sibling tool list_relay_sendings by domain.

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 ('audit which transactional emails were sent') and names two specific alternatives: 'For mail relay sendings, use list_relay_sendings instead' and 'For a comprehensive delivery report... use check_email_delivery'.

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