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

Annotations already declare readOnlyHint=true, destructiveHint=false, idempotentHint=true, and the description is consistent with that: "opens nothing by itself." It adds real value beyond the annotations by stating the return shape (step-by-step screens, buttons, fields) and the reason browser automation is required (Kahunas publishes no API docs). A 5 would need a note on what happens if the screens differ from the guide, or whether the guide is versioned.

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 caveat (returns a guide, does nothing) is front-loaded, which is good, but the final fragment "Kahunas's official API: Kahunas publishes no API docs" is redundant and grammatically broken. The opening clause "from ChatGPT, Claude or any AI agent" is filler that adds no decision-relevant 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?

For a zero-parameter, read-only guide tool with annotations and no output schema, the description covers what it returns and what it does not do, which is what an agent needs. The remaining gap is that it does not say whether the returned steps are stable/canonical or how to proceed if the browser session shows a different UI.

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 input schema has zero parameters, so there is nothing for the description to disambiguate — baseline 4 applies. It does at least make clear the tool is parameterless by describing no inputs and deferring all user-specific action to the browser tools.

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 makes clear that despite the name, this tool does not send anything: it "Returns how to do it in Kahunas step by step (screens, buttons, fields) and opens nothing by itself." That verb+resource framing (produce a per-screen guide for sending a message in Kahunas) is specific. It stops short of 5 because it never contrasts itself with the other kahunas_* siblings (e.g. kahunas_add_client, cotlet_app_guide), so an agent must infer that those are separate action paths.

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 explicit sequencing: call this first, then "do it with the cotlet_browser_* tools in the user's Kahunas Cloud Browser" — which resolves the main ambiguity of why a guide tool exists next to browser tools. It also implies the condition (user wants to send a message in Kahunas). It omits any when-not guidance, such as cases where a direct kahunas_* action tool is the better route.

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