get_promotionFetch a promotion by ID to access discount details and campaign information for a Fourthwall shop.
Rate limit: 100 requests / 10 seconds per shop. See Rate limiting.
Returns a promotion by id
| Name | Required | Description | Default |
|---|---|---|---|
| account | No | Exact private shop profile label; not a provider identity or authorization proof. | |
| promotion_id | Yes | Native promotionId |
Changes observed during successful MCP inspections.
v2.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, idempotent, non-destructive, open-world. The description adds a concrete operational constraint (100 requests / 10 seconds per shop) with a link, which is genuinely useful context not present in structured fields.
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 short sentences with no waste; the rate-limit constraint is front-loaded. Slightly odd that the primary purpose is subordinated to the rate-limit note, but nothing is bloated.
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-resource read with full annotation coverage and full schema coverage, the essentials are present. However, there is no output schema, so the description could say more about what a returned promotion contains or how the response is shaped.
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%, so both parameters are already documented, including the 'account' caveat and promotion_id pattern. The description adds no parameter meaning 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+resource ('Returns a promotion by id'), which is unambiguous. It does not differentiate from siblings like list_promotions or update_promotion, but the singular 'by id' framing is distinct enough to infer.
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?
There is no guidance on when to use this versus list_promotions, update_promotion, or create_promotion. The only usage-adjacent content is a rate-limit note, which is a constraint, not a when-to-use signal.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.