sync_customers_to_contacts

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

With no annotations provided, the description carries the burden of behavioral disclosure. It states that the tool 'creates or updates' contacts, which is useful, but it does not disclose matching logic, idempotency, or potential deletion of existing contacts. The schema includes idempotentHint: true, but the description itself adds limited behavioral context beyond the basic write action.

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 concise sentences that directly state the tool's purpose and action. The first sentence identifies the sync direction, and the second elaborates on the create/update behavior. Every word contributes value with no redundancy or filler.

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?

The tool is a synchronization operation with no output schema, and the description gives a high-level view. However, it omits critical details such as how records are matched, whether it does a full or incremental sync, and what happens to contacts not present in Books. These gaps make it only minimally complete for a sync tool.

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% (all 3 parameters have descriptions). The description adds no parameter-specific details beyond what the schema already provides, so it earns the baseline score of 3. It does not help clarify the nested 'filters' object beyond the schema's own description.

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 uses a specific verb ('Sync') and resource ('Books customers to CRM contacts') with an explicit direction (Books → CRM). This clearly distinguishes it from sibling tools like sync_contacts_to_customers (reverse direction) and sync_accounts_to_customers (different source data).

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 provides clear context by stating the direction of sync (Books to CRM) and the operation (creates or updates). However, it does not explicitly mention when not to use it or name alternative tools, so it falls short of a 5. It does offer enough context for an agent to differentiate it from reverse-direction tools.

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