get_preferences

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

Beyond the readOnlyHint and idempotentHint annotations, the description adds meaningful behavioral detail: it reads from the in-memory ynab_resources.preferences, reflects the env > preferences.json > defaults precedence, and returns a markdown table. It also mentions the equivalent resource endpoint, giving agents a fuller understanding of side-effect-free behavior.

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 three focused sentences with the primary purpose front-loaded. Each sentence adds distinct value: the action and output format, the underlying data source and precedence, and the alternative resource access. There is no redundancy or filler.

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 zero-parameter, read-only tool with an output schema, the description is fully complete. It explains where the data comes from, how it is formatted, and provides an alternative access method, leaving nothing essential for an agent to invoke it correctly.

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?

The tool has zero parameters, and the input schema is fully covered, so per the rubric the baseline is 4. The description does not need to explain parameters, and it provides no misleading parameter-related information.

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 opens with a specific verb and resource: 'Return the current YNAB MCP preferences as a markdown table.' It clearly identifies the tool's output format and distinguishes it from sibling write tools like set_preference by emphasizing a read operation.

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 gives clear context on when to use the tool: whenever current preferences are needed, and it notes that the same content is available as a resource for clients that prefer that access path. It does not explicitly state when not to use it relative to siblings, but the read-only framing and resource alternative provide adequate guidance.

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