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

The description provides the response structure, pagination mechanism, and endpoint, adding value beyond the readOnlyHint annotation. It does not contradict annotations.

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 sentences plus endpoint, no filler. Front-loaded with the core purpose, highly efficient.

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?

Adequate for a list tool with 3 params and no output schema. Describes response format and pagination, though could mention default limit or ordering.

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%, and the description adds context by showing the response shape and how limit and starting_after work for pagination, enhancing understanding beyond the schema.

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 explicitly states 'List the contacts in a list' and specifies returned fields (id, email_address, etc.) and the endpoint, clearly distinguishing it from sibling tools like get_contact.

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?

Usage is implied via the verb 'list' and pagination details, but no explicit guidance on when to use this tool versus alternatives (e.g., get_contact for a single contact) or when not to use it.

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