contacts_list

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

With no annotations provided, the description carries the full disclosure burden. It does add one genuinely useful behavioral fact — that results are paginated and how to traverse every page — and "saved contacts" implies a read-only listing. It says nothing about required permissions, ordering, result size limits, or what happens with the default page_size of 200.

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 with zero filler, and the core purpose is front-loaded before the pagination tip. Nothing could be removed without losing information.

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?

A three-parameter tool with no annotations, no output schema, and 0% schema description coverage needs more than two sentences. The required `account` argument and the `page_size` default are unexplained, and no return-value shape or permission context is given, so the description is under-specified for the tool's complexity.

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 schema supplies no parameter meaning at all and the description must compensate. It clarifies the page_token/next_page_token relationship, which is valuable, but the required `account` parameter and `page_size` are never mentioned, leaving the most important input undocumented.

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?

"List saved contacts" gives a specific verb plus resource and is immediately understandable. It does not, however, distinguish itself from sibling tools such as contacts_search, contacts_batch_get, or other_contacts_list, so the agent must infer the boundary on its own.

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 second sentence gives concrete procedural guidance for pagination (pass next_page_token back as page_token to walk every page), which is real usage instruction. But there is no guidance on when to pick this over contacts_search or contacts_batch_get, and no exclusions or prerequisites stated.

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