Inxmail MCP

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

No annotations provided, so description carries full burden. It successfully discloses read-only nature ('Read-only') and describes return payload structure ('Returns recipient, timestamps, correlation IDs, and delivery status'). Minor gap: no mention of error conditions or rate 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?

Five short sentences with zero waste. Front-loaded with core purpose, followed by return values, usage conditions, alternative tool, and safety hint. Every sentence earns its place.

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?

For a single-parameter retrieval tool without output schema, description is complete. It compensates for missing output schema by detailing return fields, and covers the lack of annotations with explicit 'Read-only' declaration.

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 has 100% coverage (relaySendingId described), establishing baseline of 3. Description adds valuable context that the ID originates from 'list_relay_sendings', helping the agent understand the data flow.

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 ('Get full details'), resource ('mail relay sending'), and scope ('by its ID'). Clearly distinguishes from sibling tool 'get_sending' by specifying 'relay sending' and contrasting with 'event-triggered sendings'.

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?

Explicitly states when to use ('when you have a relay sending ID from list_relay_sendings') and provides clear alternative ('For event-triggered sendings, use get_sending instead'), directly addressing sibling tool selection.

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