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

Beyond the readOnlyHint/idempotentHint/destructiveHint annotations, the description discloses the return shape (screens, buttons, fields), states explicitly that nothing is opened or executed by the call, and notes that Paperless Post has no public API, which explains why the browser path is required.

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 fact (returns a guide, opens nothing) is front-loaded in the second sentence, which is the right structure. Some phrasing is filler — the ChatGPT/Claude/any-AI-agent clause and the redundant 'Paperless Post's official API: Paperless Post has no public API' — but each sentence still carries information.

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, the description carries the burden of describing the return and does so adequately (step-by-step screens, buttons, fields). It could be more complete about preconditions, such as whether the user must already be signed in or have an existing event before the guide is usable.

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 description to disambiguate; baseline 4 applies. It does not need to explain inputs, and the schema is empty by design.

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 verb and resource (send an invitation in the user's Paperless Post account) and immediately clarifies the crucial nuance that it returns step-by-step instructions rather than performing the send. That distinguishes it cleanly from the cotlet_browser_* siblings that actually execute the steps.

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 usage path: call this first to get the procedure, then execute it with the cotlet_browser_* tools in the user's Cloud Browser. It does not explicitly exclude alternatives (e.g., when to prefer paperless_post_add_guests or a direct browser workflow without this guide), so it stops short of full when/when-not guidance.

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