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

Annotations already declare readOnlyHint=true, destructiveHint=false, idempotentHint=true and openWorldHint=false, and the description is consistent with them by stating it 'opens nothing by itself.' It adds real context beyond the annotations: the return content (step-by-step screens/buttons/fields) and a note that Substack's official API is limited, which explains why a browser flow is needed.

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 core message is delivered quickly, but the 'from ChatGPT, Claude or any AI agent' clause is marketing filler and the first sentence runs several distinct ideas together, including the API caveat tacked on at the end. Front-loading the fact that this returns instructions rather than scheduling would make it sharper.

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 zero-parameter, no-output-schema guide tool, the description covers what it returns, that it performs no side effects, and which follow-up tools to use. The notable omission is the relationship to `schedule_post`, which is the main source of ambiguity in an otherwise complete definition.

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?

The tool takes zero parameters with a closed schema, so there is nothing for the description to disambiguate. Baseline of 4 applies; the description does not need to add parameter meaning.

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 states a specific resource (scheduling a post in the user's own Substack) and then clarifies the actual mechanic: it returns step-by-step instructions (screens, buttons, fields) rather than performing the action. That clarification rescues an otherwise misleading lead sentence, but it never differentiates itself from the very similar sibling tools `schedule_post` and `substack_create_post`, so an agent cannot tell from this text which one actually schedules.

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 gives a clear next-step workflow — use this for guidance, then act via the `cotlet_browser_*` tools in the user's Substack Cloud Browser — which is genuinely useful routing. However, it gives no guidance on when to pick this over the actual `schedule_post` sibling, which is the most important alternativeness decision an agent faces here.

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