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

Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so safety is covered; the description still adds real value by stating the tool 'opens nothing by itself' and returns only step-by-step screens/buttons/fields, which prevents an agent from assuming any browser action occurred. It also discloses an external dependency (SoundCloud Artist Pro credentials needed for the API route). It stops short of describing the shape of the returned guide beyond 'step by step'.

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 key constraint ('opens nothing by itself') and the next step are reasonably front-loaded, but 'from ChatGPT, Claude or any AI agent' is filler and the trailing API note with the odd '(checked 30 Oct 2026)' date adds bulk without helping the agent decide or call. A tighter version would lead with 'returns a guide, does not perform the check'.

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 zero parameters and no output schema, the description carries the burden of explaining what comes back, and it does so at a workable level ('step by step (screens, buttons, fields)'). The main remaining gap is that it never says whether the returned guide is generic or tailored to the specific user's account.

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, so the baseline is 4 and there are no parameter meanings the description needs to disambiguate. Nothing in the description contradicts the empty schema.

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 headline verb 'Check if you messaged a profile' implies the tool performs a query and returns an answer, but the second sentence reveals it only 'Returns how to do it in SoundCloud step by step (screens, buttons, fields) and opens nothing by itself'. That tension between the claimed purpose and the actual function (a how-to guide generator) leaves an agent without a crisp sense of what it will get back. It also does not distinguish itself from the sibling soundcloud_read_direct_messages.

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?

The description gives a follow-on workflow ('then do it with the cotlet_browser_* tools in the user's SoundCloud Cloud Browser') and explains why the official API is not an option (Artist Pro subscription required for app credentials). That is useful routing context, but there is no explicit when-not-to-use guidance and no named MCP alternative for actually reading messages.

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