Retrieve bounced email messages with filters and pagination to manage delivery issues.
List bounced messages, filtered and paginated.
| Name | Required | Description | Default |
|---|---|---|---|
| tag | No | Tag filter | |
| page | No | Page number (1-based) | |
| query | No | Substring match on subject / addresses | |
| status | No | Status filter | |
| per_page | No | Results per page (max 100) |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description adds 'filtered and paginated,' which is a behavioral trait, but this is already implied by the parameter names and schema. It does not disclose non-obvious behaviors such as the default result set, whether bounces are scoped to a particular stream or user, or the shape of returned data. The annotations (readOnlyHint, openWorldHint) cover safety but not these details.
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?
The description is a single front-loaded sentence with no filler. It conveys the verb, resource, and key behaviors efficiently. Every word 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?
Despite having no output schema, the description does not explain what a bounce record contains or what the response format is. It also omits whether pagination has a default order or whether filters are inclusive/exclusive. For a list tool with five optional parameters, this leaves meaningful gaps for an agent to resolve correctly.
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%, so parameters are fully documented in the schema. The description adds a conceptual grouping ('filtered' maps to tag/query/status; 'paginated' maps to page/per_page), but does not add meaning beyond the schema's individual descriptions. This meets the baseline for high coverage.
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 clear verb ('List') and a specific resource ('bounced messages'), which distinguishes it from siblings like list_emails and list_inbound. It implies filtering and pagination, but does not explicitly contrast it with other list tools or state the exact scope (e.g., global vs. per-stream), so it stops short of full sibling differentiation.
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?
No guidance is provided on when to use this tool versus list_emails, get_email, or list_inbound. The description simply states the resource and behavior, leaving the agent to infer selection from the name. There are no explicit conditions, alternatives, or exclusions.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.