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

Annotations already indicate readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the description does not need to restate safety. The description adds some context by noting the operation works on 'indexed document names' with substring matching, but it does not disclose other behavioral details like pagination or result limits, which is acceptable given the 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 a single concise sentence that front-loads the main action and scope. There is no filler or redundant wording, so every word 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?

For a simple read-only listing tool with an output schema and strong annotations, the description covers the core operation adequately. It is incomplete in that it does not address usage relative to sibling search tools or clarify the max_results parameter, but given the tool's low complexity this is a moderate gap rather than a severe one.

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 0%, so the description must compensate for undocumented parameters. It indirectly explains the 'contains' parameter through 'matching a substring', but it gives no semantic guidance for 'max_results', leaving one of two parameters effectively unexplained.

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 verb ('List'), resource ('indexed document names'), and filter ('matching a substring'), which clearly conveys the tool's purpose. It does not explicitly distinguish itself from sibling tools like search or find_exact_text, but the emphasis on document names makes the scope reasonably clear.

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 the tool: when you want document names containing a particular substring. However, it provides no explicit guidance about when not to use it or how it compares to sibling tools such as search or find_exact_text, so the guidance is minimally adequate.

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