List Contacts

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

No annotations are provided, so the description must carry the behavioral burden. It omits any mention of read-only nature, authentication requirements, rate limits, error behavior, or pagination details beyond what the schema already provides.

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 two sentences, front-loads the core purpose, and avoids fluff. While it lacks behavioral depth, the brevity is appropriate for a straightforward list operation.

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?

Despite low complexity (4 params, no output schema), the description fails to explain pagination, result set structure, or that contact_book is required. It relies heavily on the schema, leaving the agent without important usage context.

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 coverage is 100% with descriptive parameter comments. The description adds no new semantic detail; it merely repeats the search parameter's purpose already covered in the schema. Thus it meets the baseline without exceeding it.

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 'Lists contacts in a contact book,' which clearly identifies the action and resource. It distinguishes from sibling tools like get_contact and create_contact, though it does not explicitly scope to all contacts or mention the exclusion of other filtering 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 only advises using the search parameter for name/email queries but provides no guidance on when to use this tool versus alternatives like get_contact for individual contacts or list_contact_books for book listing. No when-not-to-use context is given.

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