crm_merge_contactsMerge duplicate contacts into the one you keep. Its empty fields are filled from the others, tags and custom fields are combined (the kept contact wins where both have a value), and every note, task, email, chat, call, ticket and deal moves to it. The merged contacts are archived; their emails still find the kept contact. Costs $0.01 per call; nothing if it fails.
| Name | Required | Description | Default |
|---|---|---|---|
| keep_id | Yes | ||
| merge_ids | Yes |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already flag destructiveHint=true, but the description goes well beyond them: it explains field-filling precedence, tag/custom-field combination with the kept contact winning conflicts, migration of notes/tasks/emails/chats/calls/tickets/deals, archiving of merged records, preservation of email lookups, and the $0.01-per-call cost with no charge on failure.
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?
Four tight sentences, front-loaded with the core action and outcome before the field/record details and cost. Every clause carries actionable information with no 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?
For a destructive two-parameter mutation with no output schema, the description covers side effects, data precedence, and billing adequately. Minor gaps remain: no guidance on identifying duplicates first, the 10-record cap, or edge cases like overlapping keep/merge ids.
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 0%, yet the description only implicitly maps 'the one you keep' to keep_id and 'the others' to merge_ids, without naming them. It adds useful semantics (merged records are archived, max of 10 not mentioned) but does not fully compensate for the undocumented parameters.
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 ('merge') and resource ('duplicate contacts') plus the outcome ('into the one you keep'), which cleanly separates it from crm_merge_companies and the save/update contact tools. An agent can identify the operation without opening the schema.
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 by the name and by 'duplicate contacts', but the description never states when to call this versus crm_find_duplicates (to locate candidates) or crm_archive_contact (to discard a record without merging). No prerequisites or exclusion conditions are given.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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