Frihet MCP Server

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

Annotations already indicate this is a non-destructive, idempotent mutation (readOnlyHint=false, destructiveHint=false, idempotentHint=true). The description adds useful context about partial updates ('Only the provided fields will be changed'), which isn't captured in annotations. However, it doesn't mention authentication requirements, error conditions, or rate limits that would be helpful for a mutation tool.

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 extremely concise - just two sentences (with bilingual repetition). The first sentence states the core purpose, and the second adds important behavioral context about partial updates. There's zero wasted text, and the key information is front-loaded.

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 mutation tool with good annotations but no output schema, the description is minimally adequate. It covers the basic operation and partial update behavior, but doesn't address what happens on success/failure, return values, or error conditions. The annotations help but don't fully compensate for the lack of output documentation.

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?

With 100% schema description coverage, the input schema fully documents all 7 parameters including their types, constraints, and bilingual descriptions. The description adds no additional parameter information beyond what's already in the schema, so it meets the baseline but doesn't provide 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 verb ('Update') and resource ('an existing invoice'), making the purpose immediately understandable. However, it doesn't differentiate this tool from other update_* siblings like update_client or update_expense, which follow the same pattern. The bilingual nature doesn't add or detract from clarity.

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 provides no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites (like needing an existing invoice ID), when to use create_invoice instead, or how it differs from other update operations. The agent must infer usage from context alone.

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