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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds only that it lists documents attached to projects and supports filtering; it does not discuss auth, rate limits, or return behavior. With annotations carrying the behavioral load, a 3 is appropriate.

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?

Two short sentences, front-loaded with the core purpose and followed by the filter options. There is no filler or redundancy, and the structure is appropriate for an API list tool.

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?

The tool is a simple list operation with five optional parameters, rich read-only annotations, and no output schema. The description covers what it lists and the primary filters, though it omits mention of the search parameter and pagination behavior. Those omissions are minor because the schema documents them fully.

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%, and each of the five parameters is documented in the schema. The description mentions only project_id and folder_id filtering, adding no syntax or nuance beyond the schema. Per the high-coverage baseline, 3 is correct.

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?

States a specific verb (List) and resource (documents attached to projects), which is clear enough for an agent to identify the operation. However, it does not differentiate from related siblings such as list_project_document_folder_templates or get_project_document, so it falls short of a 5.

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 no explicit when-to-use or when-not-to-use guidance, nor does it name alternative tools. The filter hint ('Filter by project_id or folder_id') is parameter usage, not tool selection guidance. Similar to the MID calibration example, this leaves the agent to infer usage context.

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