Frihet MCP Server

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

Annotations already indicate read-only, non-destructive, and idempotent behavior. The description adds value by specifying the return content ('full invoice including line items, totals, and status'), which provides context on what data to expect beyond just the invoice ID. It doesn't detail error handling or rate limits, but with annotations covering safety, this is sufficient.

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 front-loaded with the core purpose in the first sentence, and the bilingual repetition, while slightly redundant, is concise in each language. It could be more streamlined by avoiding duplication, but it remains focused and waste-free in content.

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 simple input schema (one parameter), rich annotations (covering read-only, idempotency, etc.), and no output schema, the description is adequately complete. It specifies the return content, which compensates for the lack of output schema, though it doesn't detail error cases or response structure fully.

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%, with the parameter 'id' clearly documented as 'Invoice ID.' The description adds no additional semantic details beyond what the schema provides (e.g., format examples or validation rules), so it meets the baseline for high schema coverage without extra value.

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 specific action ('Get a single invoice by its ID') and resource ('invoice'), distinguishing it from siblings like list_invoices (which returns multiple) and search_invoices (which uses search criteria). The bilingual format reinforces but doesn't obscure the core 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 implies usage context by specifying 'by its ID,' suggesting this tool is for retrieving a known invoice rather than browsing or searching. However, it doesn't explicitly state when not to use it (e.g., vs. list_invoices for multiple invoices or search_invoices for filtering), which would elevate it to a 5.

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