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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds the meaningful domain constraint that results are scoped to the same contact and are valid merge targets, but says nothing about ordering, result limits, or what happens if no candidates exist.

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?

A single tight sentence with no filler, and the scoping constraint (same contact) is front-loaded before the cross-reference to merge_conversations. It reads as a sentence fragment rather than a complete statement, which slightly hurts clarity but not conciseness.

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 single-parameter, read-only lookup with no output schema, the description covers what is listed, the scope of the results, and the downstream tool it feeds. Only minor details (result ordering, empty-case behavior) are missing, which is acceptable at this complexity.

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% and there is only one parameter, whose schema description already explains that conversationId comes from list_conversations. The description adds no syntax, format, or constraint detail beyond that, so the baseline of 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 the exact resource — the same contact's other conversations that this one can be merged into — which is specific enough to distinguish it from siblings like list_conversations or merge_conversations itself. It lacks an explicit verb (the action is only implied by the name/title), but the scope is unambiguous.

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?

'for merge_conversations' implies this is a prerequisite lookup step before a merge, which is useful routing context. However, it never states when not to use it, what to do if the list is empty, or how it relates to list_conversations as the entry point.

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