list_addressbooks

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

Annotations already establish the read-only, idempotent, non-destructive profile. The description adds meaningful behavioral context beyond that: it filters to user-owned books and excludes system books, and it specifies the exact fields returned (id, name, description, ctag). This helps an agent predict the response content without relying solely on the output schema.

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 tight and front-loaded: a one-sentence definition, a clarifier about what is excluded, and a compact return format line. No filler or redundant explanation exists.

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 zero-parameter, read-only tool with annotations covering safety and an output schema available, the description covers everything needed to invoke it correctly: scope, filtering behavior, and return fields. There are no missing prerequisites, side effects, or edge-case instructions that an agent would need.

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?

There are zero parameters, so no parameter documentation is needed; the baseline for 0-param tools is 4. The description appropriately uses its space to describe the return value instead of inventing parameter 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 states a specific verb ('List'), a resource ('address books'), and a clear scope ('for the current user'), making its intent unambiguous. The explicit exclusion of system-generated books like 'Accounts' and 'Recently Contacted' further distinguishes it from any generic address-book listing and from sibling list tools.

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 clear context: it is scoped to user-owned address books and excludes system-generated ones, so an agent knows what kind of data to expect. It does not explicitly name alternative tools or state when not to use it, but for a simple zero-parameter listing tool this context is sufficient.

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