yazio-mcp

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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the agent knows this is a safe, repeatable read operation. The description adds the date-specific constraint, which is useful context beyond annotations. However, it doesn't describe return format, error conditions, or data freshness - leaving behavioral gaps despite annotation coverage.

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 with zero wasted words. It's appropriately sized for a simple retrieval tool and front-loads the essential information without unnecessary elaboration.

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 simple read operation with good annotation coverage (readOnly, idempotent) and full schema documentation, the description is minimally adequate. However, without an output schema, the description should ideally mention what data structure or units are returned (e.g., milliliters, ounces, timestamped entries). The current description leaves return values unspecified.

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 schema fully documents the single 'date' parameter with format and pattern details. The description mentions 'specific date' but adds no additional semantic context beyond what the schema provides. Baseline 3 is appropriate when schema does the heavy lifting.

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 ('water intake data') with a specific scope ('for a specific date'), which distinguishes it from general data retrieval tools. However, it doesn't explicitly differentiate from sibling tools like 'get_user_daily_summary' which might also contain water intake information.

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 like 'get_user_daily_summary' or 'get_user_consumed_items' (which might include water intake). There's no mention of prerequisites, constraints, or comparative use cases with sibling tools.

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