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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds the notable fact that it exposes PII (email, phone) and aggregates responses 'across all projects', but says nothing about permissions, rate limits, or pagination for the response list.

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 tight sentences with zero filler; the resource and its returned fields are front-loaded, and the ID prerequisite follows immediately.

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?

With an output schema present, the description needn't enumerate return values, and annotations carry the safety profile, so remaining needs are small. The one-parameter schema is fully documented, leaving only minor gaps around pagination of the 'recent responses' set.

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 single contactId parameter is fully documented in the schema, including its 'from contact_list' provenance. The description's 'Resolve contact ids via contact_list' repeats that schema note rather than adding syntax or format detail, so the baseline 3 applies.

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 names a specific resource and scope: 'One contact (respondent)' with a concrete inventory of returned fields (name, email, phone, recent responses). The singular 'One contact' cleanly distinguishes it from the plural sibling contact_list.

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?

It explicitly routes the agent to contact_list for ID resolution, establishing the prerequisite for calling this tool. However, it doesn't state when to prefer this detail view over the list view or other response-level siblings like response_detail.

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