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

The readOnlyHint annotation already signals this is a safe read operation. The description adds the context of 'not inside a folder' and the REST endpoint, but does not disclose other behaviors like pagination, rate limits, or response structure. This is adequate but not rich.

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 short sentences: one defining the tool's purpose and one indicating the underlying REST endpoint. No unnecessary words or repetition, making it highly concise and well-structured.

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 operation with 2 parameters and no output schema, the description covers the essential purpose and endpoint. It lacks explicit mention of return format or pagination, but the schema handles parameter details. Overall, it is sufficiently complete for its simplicity, though it could hint at response contents.

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% for both parameters (space_id, archived). The description does not add any parameter-specific meaning beyond what the schema already provides, so it meets the baseline but does not exceed it.

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 tool lists lists that live directly in a space, explicitly excluding folders. This provides a specific verb ('List'), resource ('lists'), and scope ('folderless'), distinguishing it from sibling tools like list_lists that might include all lists.

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 when to use this tool (for lists directly in a space, not inside a folder) and distinguishes it from a general list tool. However, it does not explicitly name alternatives or state 'use this instead of list_lists when...', so it lacks the explicit exclusions needed for a 5.

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