Read the local send receipt for an operationKey to verify API acceptance or identify pending status that must be reconciled before retry.
Read the local receipt for an operationKey. accepted means API acceptance; pending requires reconciliation before any retry.
| Name | Required | Description | Default |
|---|---|---|---|
| operationKey | Yes | Stable unique key for this exact send. Reuse for retries; never change it after an uncertain result. |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the bar is lower. The description adds genuinely useful context beyond them: the receipt is local (not an authoritative server round-trip) and defines two return states, 'accepted' as API acceptance and 'pending' as requiring reconciliation.
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 dense sentences, zero filler, with the core action and the meaning of each status front-loaded in the order an agent needs them.
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?
No output schema exists, so the description should convey the return states; it explains 'accepted' and 'pending' but does not enumerate other possible states (e.g., rejected, unknown) or the staleness implications of reading a local receipt. For a one-parameter read tool this is close to complete.
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 operationKey description already covers stability, reuse on retry, and immutability after uncertain results. The description confirms the key scopes a single send but adds no syntax or format detail beyond the schema, so the baseline 3 applies.
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 ('Read the local receipt for an operationKey') and the word 'local' implicitly contrasts with server/API status checks. It does not, however, name or differentiate itself from the sibling mail_status, which an agent could easily confuse with a send-status lookup.
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?
The description gives an operational rule tied to a result state ('pending requires reconciliation before any retry'), which implies this is the tool to call after an uncertain send. It never states when to prefer it over mail_status or what to do if the key is unknown, so selection guidance is only implied.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.