yazio-mcp

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

Annotations already declare readOnlyHint=false and idempotentHint=false, indicating this is a non-idempotent write operation. The description adds the behavioral context of 'adding to a log,' which implies persistence and mutation, but doesn't provide additional behavioral details like whether duplicates are allowed, what happens on invalid product_id, or how the system handles conflicts. The description doesn't contradict annotations, but adds minimal value beyond them.

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 a single, efficient sentence that directly states the tool's purpose without any fluff or redundant information. It's appropriately sized and front-loaded with the core action, making it easy to parse quickly.

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 6 parameters and no output schema, the description is minimally adequate. It states what the tool does, but lacks context about prerequisites, error conditions, or what happens after the add operation. With annotations covering safety (non-readOnly) and idempotency, and schema covering parameters, the description fills basic gaps but doesn't provide a complete picture for effective use.

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 all parameters well-documented in the schema itself (e.g., product_id as UUID, date format, daytime enum values, amount in base units). The description adds no parameter-specific information beyond what's already in the schema, so it meets the baseline for high schema coverage without compensating with additional semantic context.

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 ('Add') and resource ('food item to user consumption log'), providing a specific verb+resource combination. However, it doesn't explicitly distinguish this tool from its sibling 'remove_user_consumed_item' beyond the obvious add/remove difference, nor does it clarify how it differs from 'add_user_water_intake' in the broader context of consumption logging.

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 a valid product_id from 'get_product' or 'search_products'), nor does it clarify when to use this versus 'add_user_water_intake' for different consumption types. There's no explicit when/when-not guidance or named alternatives.

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