merge_contacts

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

Without annotations, the description must disclose all behavioral traits. It fails to specify whether the secondary contact is deleted after merging, nor does it mention any side effects (e.g., on conversations, tags, or lifecycle). This is a significant gap for a mutation tool.

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-loading the core action. Every sentence adds value without redundancy. It is appropriately sized for the tool's complexity.

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?

No output schema is provided, so the description should indicate the return value (e.g., the merged contact). It does not. Additionally, given sibling tools like update_contact, more context on when to merge vs update would improve completeness.

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%, so the baseline is 3. The description adds no additional meaning beyond the schema; it only restates that fields can be optionally updated, which is already clear from the schema's descriptions.

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 clearly states 'Merge two contacts' and explains that the primary is kept and secondary merged, with optional field updates. This distinguishes it from sibling tools like update_contact (single contact) and create_contact (new 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?

The description does not provide guidance on when to use merge vs. updating or deleting contacts. No explicit when-to-use or when-not-to-use information is given, leaving the agent to infer usage context.

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