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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is covered. The description adds the return structure (folders array with fields) and the reuse context, which goes beyond annotations. No contradictions. A 4 is appropriate because the description contributes useful behavioral context on top of 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 sentences, front-loaded with the purpose and immediately followed by usage guidance and return format. No fluff, every sentence earns its place. The structure is efficient and easy to scan.

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, parameterless read-only tool with an output schema, the description covers the purpose, usage timing, return structure, and even provides a reason to call it. Nothing an agent needs to invoke it correctly is missing. The description is complete and self-sufficient.

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 there is nothing to describe. Schema coverage is trivially 100%. The baseline for 0 params is 4, and the description does not need to add parameter information since none exist. It correctly omits any param details.

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 it lists folders used for grouping intakes by client/project, with a specific verb and resource. It distinguishes itself from siblings by naming when to call it (before create_folder, etc.) and why (reuse existing folder). This fully clarifies the tool's purpose and differentiates it from alternatives.

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 explicitly instructs when to use the tool: 'Call this before create_folder or before setting folder_id on define_intake, update_intake, or list_intakes.' It also provides an anti-pattern (avoid creating duplicates) and names the alternative action (reuse existing folder). This is exemplary usage guidance.

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