List own contacts

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

Annotations already provide readOnlyHint=true and openWorldHint=true, covering the read-only safety profile. The description adds no extra behavioral context such as pagination, ordering, or the effect of accountId, so it meets but does not exceed the baseline.

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 with no redundant information, front-loading the purpose effectively.

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?

Although the tool is simple and annotations are present, the description completely omits the accountId parameter's meaning and provides no usage distinction from search_contacts. The lack of any parameter documentation makes the description incomplete for effective tool 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?

The input schema has one parameter (accountId) with 0% description coverage, and the description does not mention accountId at all. Since the description must compensate for low schema coverage but doesn't, this is a significant gap.

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 uses a specific verb 'List' with a clear resource 'all users in the contact book', making its primary function unambiguous. It distinguishes from sibling list_accounts and search_contacts, though it could more explicitly state 'own' contacts.

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 this is the tool to use when you need the full list of contacts, but it provides no explicit when-to-use guidance or alternatives such as search_contacts for filtered queries. No exclusions are stated.

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