List contacts

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

Annotations already mark this as read-only, idempotent, and non-destructive, and the description adds substantial behavioral context: absent person_fields may be unmasked rather than empty, deleted people carry metadata.deleted=true, sync tokens expire after ~7 days with HTTP 410, and pagination behavior is described. No contradiction with 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?

The description is dense but appropriately sized for a complex listing tool with no output schema. It is front-loaded with the core purpose, then covers pagination, incremental sync, error behavior, and exclusions without wasted words.

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 no output schema, the description fully explains the return structure: connections[], resourceName, etag, person_fields, nextPageToken, totalItems, and nextSyncToken. It also covers pagination, sync token usage, expiration errors, and scope exclusions, making it complete for correct 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?

Schema coverage is 100%, so the schema already documents each parameter. The description still adds meaningful semantics beyond the schema, such as default person_fields, absent-field masking behavior, sync token expiry, and pagination flow. It does not add new detail for sort_order, but the schema already covers that.

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?

States a specific verb and resource: 'Lists the account's saved contacts (People API people/me/connections)'. It also distinguishes itself from siblings by explicitly excluding the Workspace directory and auto-saved addresses, pointing to list_other_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?

Clearly defines when this tool is appropriate: for the user's own saved contacts, and explicitly says it is not for the Workspace directory or auto-saved addresses, naming the sibling alternative. It also explains when to use incremental sync via sync_token and request_sync_token.

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