Create Event Subscription

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

Annotations already declare non-read-only, open-world and non-idempotent, but the description adds genuine context beyond them: the server verifies signatures without hosting a receiver, and the receiver must ack with 200/204 within 5 seconds and enqueue asynchronously. It does not cover auth requirements or the return shape, but the role clarification is a meaningful value-add.

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?

Two sentences, front-loaded with the core purpose before the operational caveat. The second sentence is somewhat procedural and duplicates schema text for callbackUrl, costing a little tightness, but there is no filler.

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 two-parameter create tool with a fully described schema and no output schema, the description supplies enough context to call it correctly: what it registers, the external receiver requirement, and the acknowledgment contract. It could note the sibling verify/get tools for follow-up, but nothing essential is missing.

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?

With 100% schema description coverage, the schema already documents both eventType (with documented values) and callbackUrl. The description only repeats the callback acknowledgment guidance already present in the callbackUrl param description, adding no new parameter semantics beyond the schema baseline.

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 states a specific verb and resource ('Create a Lexware webhook subscription for an external callback handler') and clarifies scope ('manages subscriptions and verifies signatures but does not host a receiver'). This is clear and distinguishable from the delete/get/list subscription siblings, though it never names them explicitly.

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?

It implies the usage context by noting the MCP server does not host a receiver, so the caller must supply an external callback handler. However it never states when to use this versus lexware_verify_webhook_signature or lexware_get_event_subscription, so routing guidance is only inferred.

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