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

Annotations already declare readOnlyHint=true, so safety is covered; the description goes further with real behavioral context: per-platform capability flags (readPosts, publishPosts, schedulePosts, repostPosts), TikTok's Business Developers requirement, Instagram/YouTube/Facebook scope requirements, and which platforms do not support reposting. It does not describe ordering, pagination, or error behavior for disconnected accounts.

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 purpose is front-loaded in the first sentence, but the body is padded by a repeated pattern — 'X reposting is not supported' appears four separate times — that could be stated once. The capability matrix is useful but could be compressed into a single sentence rather than one per platform.

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 read-only, single-optional-parameter list tool with no output schema, the description covers what is returned (accountId plus per-account capability flags) and the default scoping behavior, which is what an agent needs. Minor omissions such as ordering or behavior for zero connected accounts keep it from a 5.

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 the single workspaceId parameter is fully documented in the schema, including the 'omit to list all' default. The description restates that default rather than adding syntax or format detail, so the baseline of 3 is appropriate.

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 first sentence gives a specific verb plus resource ('List ... accounts connected to a Posteady workspace') and names the seven platforms covered. It is clearly distinguishable from siblings like list_workspaces and list_posts, especially since it states it returns accountId values used by list_posts.

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?

It states the default behavior (all workspaces, each labeled) and the narrowing condition (pass workspaceId), and explains that the returned accountId feeds list_posts and write actions. It does not explicitly say when *not* to use it or name an alternative tool, so it falls short of the top score.

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