List Contacts

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

Annotations already declare read-only, idempotent, non-destructive behavior. The description adds the scope constraint 'for the authenticated user,' which is useful context beyond the annotations. However, it does not disclose pagination behavior, default ordering, or what fields are returned, so it provides limited additional behavioral detail.

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, clear sentence with no filler or redundancy. It is appropriately sized for a simple list operation and front-loads the key action and scope.

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?

Given the strong annotations, complete parameter descriptions, and presence of an output schema, the description is mostly sufficient for a straightforward read-only list. It clearly states the resource and user scope, though it lacks alternative-tool guidance, which is covered under usage guidelines rather than completeness.

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 100%, so the schema already documents all parameters, including defaults and token semantics. The description does not add extra meaning beyond the schema, resulting in the baseline score of 3.

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 and resource: 'List contacts for the authenticated user.' This clearly conveys the tool's function. However, it does not explicitly differentiate from sibling tools like search_contacts or get_contact, so it falls short of a 5.

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?

No guidance is provided about when to use this tool versus alternatives such as search_contacts or get_contact. The description only states what it does, leaving the agent to infer usage context without explicit exclusions or recommendations.

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