contacts_sync

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

Annotations already declare readOnlyHint=false, destructiveHint=false, and openWorldHint=true, so the safety profile is partially covered. The description's parenthetical adds implementation plumbing (POST path, gRPC method, socket name) rather than behavior: it does not say whether the import merges with or replaces existing channel contacts, whether it is idempotent, or what permissions are required for a mutation operation.

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 front-loaded sentence with the endpoint details tucked into a parenthetical. It is tight and wastes little; the parenthetical is arguably useful to a developer agent, though borderline extraneous for tool selection.

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 one-parameter mutation tool with no output schema, the description covers the core action but leaves the required channelId undocumented and omits the effect on existing contacts. It is minimally adequate rather than complete.

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% for the single required parameter channelId. The phrase 'for a channel' loosely implies the parameter selects the target channel, but the description provides no format, source-of-contacts, or example details to compensate for the schema gap.

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 states a specific verb and resource: 'Import the platform's address book for a channel.' An agent can tell it is a bulk import of contacts into a channel context. However, it never distinguishes itself from siblings like contacts_create, contacts_list, or contacts_search, so differentiation relies on the reader's prior knowledge.

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?

There is no when-to-use guidance, no prerequisites, and no mention of alternatives. The agent is not told when to sync versus create, list, or search contacts, nor what preconditions (existing channel, prior authentication) must hold.

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