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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and closed-world, so the safety profile needs no repetition. The description adds genuinely new behavior: the result is a snapshot of limits and credits, and connection state can change between calls, which is why it must be re-invoked. It stops short of describing result shape or failure modes, which keeps it at 4.

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?

Three sentences, front-loaded with the action, then the returned fields, then the conditional follow-up workflow. Every clause carries operative information — the platform list, the credit/limit concepts, and the connect_url loop are each load-bearing.

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 takes on the job of naming what comes back (platforms, connections, limits, cost, credits) and does so. Combined with the connect-then-retry instruction, an agent has everything needed to call it and act on the result.

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?

Zero parameters, so there is no argument semantics to convey and the baseline of 4 applies. The description correctly implies the user is resolved from context rather than passed as an argument.

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?

Names a specific verb ('Check') and a specific resource (publishing readiness) and then enumerates exactly what the check covers: offered platforms, connected accounts, today's YouTube limit, X credit cost, and the user's credits. This separates it from generic siblings like get_account_status or get_job_status without needing to see their schemas.

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?

Gives explicit call ordering ('before offering to publish and before publish_video') and a named alternative flow for the empty case: hand over `connect_url`, note that connecting requires a browser sign-in, and re-call once the user confirms. When-to-use, what-to-do-next, and the prerequisite are all stated.

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