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

Annotations cover the safety profile (readOnlyHint=true, openWorldHint=true, destructiveHint=false), leaving the description to add operational context, which it does: it explains that needsReconnect means the network refused the sign-in and that signIn.endsSoon flags a sign-in expiring within a week. It goes beyond repetition by telling the agent what to do with those flags, though it doesn't describe the full response shape.

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?

Every sentence carries actionable information and the refresh guidance is front-loaded. The opening noun phrase ('The owner's connected accounts, with the channel IDs...') is a fragment that reads awkwardly, but overall there is 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?

There is no output schema, so the description must carry the return-value burden. It explains three response signals (channel IDs, needsReconnect, signIn.endsSoon/endsAt) but omits other likely fields, ordering, and pagination, so an agent still cannot predict the full response.

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%, so the baseline is 3. The description earns above baseline by adding timing semantics the schema lacks — the exact moment to use refresh: true (just after a person connects an account) and what it changes (re-read from provider vs. local copy).

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 identifies the resource precisely — the owner's connected accounts and the channel IDs used in a post — so an agent can infer it returns connected accounts. It never uses an explicit verb like 'list' and offers no direct comparison to the nearby list_platforms, which an agent could easily confuse with it, so it stops short of a 5.

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 guidance is present but only for the refresh parameter ('pass refresh: true after a person has just connected something'), not for tool selection. It never states when to call this versus list_platforms or whoami, so the when-to-use layer is left to inference.

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