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

Annotations already declare read-only/idempotent/non-destructive, and the description adds substantial behavioral context beyond them: the per-platform entry shape, the meaning of defaultAccountId, the accountChoiceRequired flag and required follow-up action, and the fact that no tool connects accounts or sets defaults (that happens in Narrareach Settings).

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?

Dense but front-loaded: the core purpose and return shape come first, then the routing alternatives, then the account-choice rule. Every sentence carries distinct guidance 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?

An output schema exists, yet the description still explains the returned fields relevant to the follow-up call (accountId, defaultAccountId, accountChoiceRequired). Combined with sibling routing and the Settings caveat, nothing needed to call or chain the tool is missing.

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 coverage is 100% for both optional parameters (writer, workspace), so the schema carries the semantics and baseline 3 applies. The description references socialAccountIds and accountId, but those belong to schedule_note rather than this tool's inputs, so it adds no direct meaning to writer/workspace.

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 ('List') and resource ('connected Threads, Facebook, TikTok, Pinterest and X accounts a Note can be sent to'), including the platform scope that separates it from its Instagram/LinkedIn counterparts. An agent can identify the tool 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?

Names the sibling alternatives explicitly (list_instagram_destinations, list_linkedin_destinations) and explains the downstream condition: when accountChoiceRequired is true, ask the writer and pass the chosen account in schedule_note.socialAccountIds. It also documents the X-only-when-multiple-connections edge case.

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