list_resources

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

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint, so the safety profile is covered. The description adds modest context about resource categories but does not disclose behavior beyond what the annotations and zero-parameter schema make obvious, such as return format or pagination.

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?

A single, front-loaded sentence that immediately conveys the action and scope. The parenthetical examples are brief and useful without adding unnecessary noise.

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 listing tool with an output schema and safe-read annotations, the description is sufficient. It establishes the exhaustive scope ('all registered') and gives examples of what counts as a resource, though it does not mention output shape or caveats.

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?

There are zero parameters and the schema is essentially empty, so the baseline of 4 applies. The description adds no parameter-level detail, but none is needed.

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 uses a specific verb and resource: 'List all registered MCP resources.' It clearly distinguishes the tool from siblings like list_available_groups and list_tools_by_capability by focusing on 'resources' and illustrating with 'capability map, dispatcher catalogues, reference data.'

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 implies usage ('list all registered resources') but does not explicitly state when to choose this tool over related meta-tools such as list_available_groups or list_tools_by_capability, nor does it provide any exclusions or alternatives.

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