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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, and the description reinforces this by stating the tool opens nothing and only returns instructions. It also notes the official API/MCP server cannot build or send campaigns, which is useful context. However, it does not describe what the step-by-step output looks like or how errors/missing subscribers are surfaced.

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 instruction and handoff are front-loaded and clear, but the trailing API/MCP-server sentence adds tangential detail with an odd future date and is not needed to call the tool. The middle clause is dense but functional.

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, read-only guidance tool, the description gives the essential contract: it returns instructions, performs no action, and must be followed by browser tools. The remaining gap is how the returned steps should be consumed or what the output contains, though the no-output-schema status means a brief summary would still help.

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 there is nothing for the schema to document and the baseline is 4. The description still conveys the implicit scope, that the search targets the user's own Postscript account, which is the semantic detail an agent needs.

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?

States a specific verb and resource (find subscriber) scoped to the user's own Postscript account, which distinguishes it from account-agnostic or write-oriented siblings. It does not contrast itself with the sibling postscript_reply_to_subscriber, leaving some differentiation to inference.

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 says the tool only returns step-by-step instructions and opens nothing itself, then directs the agent to use cotlet_browser_* tools to actually perform the action. That is clear routing and a stated handoff, though it does not say when to prefer this over cotlet_browser_find for locating something on screen.

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