Fire a preset's test event through a source, like Stripe checkout.session.completed, to verify a fix end-to-end with a real event. Requires a read+write token.
Fire a preset's test event through a source (e.g. a Stripe checkout.session.completed) — a REAL event in the REAL lane, useful to verify a fix end-to-end. Requires a read+write token.
| Name | Required | Description | Default |
|---|---|---|---|
| source | Yes | source id or name (unique prefix works) |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Adds meaningful context beyond the readOnlyHint=false annotation: it emphasizes the event is REAL and side-effecting in the REAL lane, and states the auth requirement (read+write token). That auth prerequisite is exactly the kind of information the annotation does not carry.
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?
Compact single sentence with the action front-loaded, followed by the effect warning and auth requirement. No filler, though the em-dash clauses make it slightly dense.
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 one-parameter mutation tool with no output schema, the description covers the key agent concerns: it mutates real state and requires a read+write token. Return format is unspecified but not critical here.
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% and the single 'source' parameter is fully documented in the schema, so baseline 3 applies. The description's Stripe example adds mild flavor but no syntax beyond what the schema provides.
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 a specific verb and resource ('Fire a preset's test event through a source') with a concrete example event. The 'REAL event in the REAL lane' framing implicitly distinguishes it from the replay sibling, but no sibling is named 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?
Gives a use case ('verify a fix end-to-end') but never states when not to use it or points to replay/list_failed as alternatives. Usage is implied rather than routed.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.