MPStats Warehouse Stock

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

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint, but the description adds substantial behavioral context: auth requirements, specific error types (BadRequestError, AuthMissingError, RateLimitedError, etc.), and data semantics like "Missing stock counts are None, never 0." No contradictions with annotations.

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 well-structured with clear sections for return format and error format. It is appropriately detailed without redundancy. Every sentence adds helpful information, from the auth requirement to the behavior of missing data (None, never 0). The use of formatting (code highlights, headings) enhances readability.

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 an output schema, the description thoroughly explains the return structure and also enumerates all relevant error scenarios. It covers prerequisites (paid MPStats account), parameter scope, and edge cases. For a tool with two parameters and a moderate complexity, this is complete and self-sufficient.

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%, with descriptions for both skus and place. The tool description adds a bit of context, such as "place determines which MPStats dataset the SKUs resolve against," but this is also present in the schema. The description does not significantly enrich parameter understanding beyond the schema's existing 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 opens with a specific verb and resource: "Fetch per-SKU warehouse stock split from MPStats (Ozon or Wildberries)." It clearly distinguishes this tool from siblings by focusing on warehouse stock split, a niche capability. The return fields (FBS, FBO, etc.) further solidify a distinct purpose.

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 implicitly communicates when to use this tool by stating what it returns and the required environment variable (MPSTATS_MP_AUTH). It does not explicitly name alternatives or exclusions, but the context of fetching per-SKU stock split from MPStats is clear. The presence of sibling tools like mpstats_item suggests different use cases, but that contrast is not explicitly stated.

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