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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so the safety profile is covered. The description usefully adds that nothing is opened or mutated and that execution happens through cotlet_browser_* tools, plus a caveat about Sleeper's limited official API — but the API note is vague and undated in any actionable way ('checked 28 Oct 2026'), and it never says what the returned steps actually look like or whether they depend on prior conversation context.

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 with the key behavioral caveat front-loaded, but 'from ChatGPT, Claude or any AI agent' is marketing filler that costs a sentence-fragment without helping selection. The trailing API note reads as an unfinished thought and would be better as a concrete constraint or dropped.

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?

With no output schema and no parameters, the description carries the burden of explaining what comes back and how the tool resolves the target lineup; it does the former loosely ('screens, buttons, fields') and ignores the latter entirely. Annotations cover safety, so the remaining gap is the implicit reliance on conversational context, which an agent must guess at.

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 and 100% schema coverage, so there is nothing for the description to disambiguate at the schema level; baseline 4 applies. The one unaddressed question — how the tool knows which league/roster/lineup is meant with no inputs — is a completeness issue rather than a parameter-documentation one.

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 opening states a specific verb+resource (set lineup in the user's Sleeper account), and the second sentence immediately corrects the natural reading by specifying that the tool returns step-by-step instructions and 'opens nothing by itself'. The distinction from the sleeper_* league/trade siblings is clear, though the true nature of the tool (a how-to generator, not an actor) would land faster if it were the first clause rather than the second.

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?

Explicitly routes the agent to the next step: 'then do it with the cotlet_browser_* tools in the user's Sleeper Cloud Browser', which tells an agent both what this tool is for and what to do after it. It stops short of naming when NOT to use it or how it differs from the cotlet_app_guide sibling, which would have pushed this to a 5.

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