Catalog (freely callable)

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so safety is covered. The description adds behavioral context by explaining that calling without params yields global data and that it can serve as a navigation root, which is beyond the structured annotations. It does not mention auth or rate limits, but these are not expected given the annotations.

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 short paragraphs: main purpose, two usage scenarios, and a next-step pointer. Every sentence earns its place, with no filler. The structure is front-loaded with the core function and then provides clear usage instructions.

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 list tool with 3 optional parameters, an output schema, and safety annotations, the description is complete. It explains both primary invocation modes, and the existing output schema covers the return format. The description, schema, and annotations together provide sufficient context for an agent to select and invoke this tool 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?

Schema description coverage is 100%, so the baseline is 3. The description adds some meaning by explaining the 'with make only' pattern and the global no-param case, but it does not elaborate on individual parameters (especially region, which is only in the schema). Since the schema already describes each parameter, the description adds minimal extra semantic value beyond call semantics.

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+resource: 'List available years, optionally filtered by make and model.' This clearly states the tool's function and distinguishes it from sibling list tools by focusing on years as the output. It also mentions two distinct call patterns (global and filtered), reinforcing 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 gives explicit usage guidance: 'Can be called without params to get all years globally' and 'Can also be called with make only to get years for that brand', framing it as an alternative starting point for navigation. It also directs the user to ws_list_modifications after obtaining a year, indicating next steps in a workflow.

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