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

Annotations already provide readOnlyHint, openWorldHint, idempotentHint, and destructiveHint, covering safety and idempotency. The description adds value by explaining the output structure: 'Returns JSON with resource metadata' and the distinction between 'uri' and 'uri_template' fields, which is useful behavioral context beyond what annotations state.

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 two sentences with zero filler. The first sentence states the core purpose, and the second adds the crucial detail about output fields. It is front-loaded and every sentence earns its place.

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?

With no parameters and an output schema present, the description is complete for an agent to understand when and how to call this tool. It explains what it lists and the format of the output. The presence of an output schema means the description does not need to detail return values further, but it still gives a helpful preview.

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, so the baseline for this dimension is 4. The description does not need to explain parameters because there are none, and the schema confirms an empty object. No additional parameter semantics are required.

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 states a specific action and target: 'List all available resources and resource templates.' It clearly distinguishes static resources (with 'uri') from templates (with 'uri_template'), which helps differentiate from siblings like read_resource that fetch a specific resource. The verb 'List' and the resource type are unambiguous.

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 clearly implies this tool is for enumeration, but it does not explicitly state when to use it over alternatives or mention any exclusion criteria. It does not say, for example, 'Use this to discover resources before calling read_resource.' While the purpose is clear, the guidance is implicit rather than explicit.

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