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

Annotations already declare destructiveHint=true, idempotentHint=true, and openWorldHint=true, so the safety profile is covered. The description adds valuable behavioral context beyond annotations: it requires a connected account, a specific OAuth scope, tier limits, and most importantly, that the expectedUpdatedAt value from a previous read must be supplied for optimistic concurrency control. This is meaningful transparency not present in structured fields.

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?

Four sentences, each earning its place: purpose, concurrency token requirement, authentication/authorization, and tier limits. The purpose is front-loaded, and there is no redundant or vague wording.

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 has an output schema and rich annotations, so the description need not explain return values. It covers purpose, key parameter behavior, auth, and limits. A minor gap is that it doesn't state that at least one of title or description must be supplied (schema marks both optional), but overall it is complete enough for correct invocation.

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. It explains that 'expectedUpdatedAt' should be the updatedAt value from a list read, clarifying its role as a concurrency token. It also indicates that title and description are the editable fields. While it doesn't detail listId (obvious from name) or that title/description are optional, it adds critical meaning for the most non-obvious parameter.

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 ('Edit'), resource ('title or description of one owned list'), and scope ('owned', 'one'), which clearly distinguishes it from siblings like create_list, get_list, and update_listing. An agent can identify the tool's purpose without opening the schema.

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 provides clear context for when to use the tool—editing title/description of an owned list—and states prerequisites (connected account, catalog:write scope, tier limits). It does not explicitly name alternatives or exclusions, but the context is sufficient for an agent to decide when to invoke it.

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