Rebillia MCP Server

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

No annotations are provided, so the description carries the full burden. It mentions the API expects a numeric productId as a string, which adds some behavioral context, but fails to disclose critical traits like whether this is a read-only operation, error handling, authentication needs, rate limits, or response format. For a tool with no annotations, this is insufficient.

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 brief and front-loaded with the core purpose, followed by API details. Both sentences are relevant, with no wasted words. It could be slightly more structured by separating usage notes, but it efficiently conveys key information without verbosity.

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?

Given the tool's low complexity (2 parameters, no output schema, no annotations), the description is minimally adequate. It covers the basic purpose and parameter nuance but lacks details on behavior, error cases, or output, which would be helpful for an agent to use it correctly in context with many sibling tools.

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 the schema fully documents both parameters. The description adds marginal value by noting that 'externalProductId' must be numeric as a string, which clarifies beyond the schema's 'numeric as string' note. However, it doesn't provide additional context like examples or constraints beyond what's in the schema, meeting 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 clearly states the action ('Get') and resource ('external product by ID'), making the purpose evident. It distinguishes from siblings like 'list_external_products' by specifying retrieval of a single item, though it doesn't explicitly contrast with other get_* tools. The inclusion of the API endpoint adds specificity.

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 alternatives like 'get_product' or 'list_external_products'. The description implies usage for fetching a specific external product, but lacks explicit context, prerequisites, or exclusions, leaving the agent to infer from the name and parameters alone.

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