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

Annotations already establish readOnly, idempotent, non-destructive and closed-world behavior, so the bar is lower. The description adds genuinely non-obvious context beyond them: the tool returns an instructional walkthrough (screens, buttons, fields) and opens nothing itself, which prevents the agent from assuming side effects occur. It still does not describe the shape or length of the returned instructions.

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 behavioral fact (returns steps, opens nothing, follow up with browser tools) is front-loaded and useful. But 'from ChatGPT, Claude or any AI agent' is promotional filler and the trailing 'Timely's official API: Timely publishes no API docs' is an awkward, undigested fragment that does not help an agent decide or invoke.

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?

Zero parameters and rich annotations mean little needs to be said, and no output schema exists, so the description should say more about what comes back. It covers the action model and the follow-up tool family but leaves the return value vague ('step by step') and does not state whether the instructions are Timely-specific to the user's account state.

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 schema declares zero properties and the description correctly describes no inputs, so there is no parameter meaning to add. Baseline 4 applies; the absence of any input also explains why the tool can only return instructions rather than a computed slot list.

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?

Names a concrete action and resource (find free slots in the user's own Timely account) and distinguishes itself from the browser tools by stating it only returns a how-to. However, the description never resolves whether any actual slot data is returned or only step-by-step instructions, and the name ('find free slots') sets an expectation the body then hedges on. An agent can guess the intent but not state it confidently.

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?

Gives real workflow context: this tool returns guidance, then the caller should perform the action with cotlet_browser_* tools in the Timely Cloud Browser. It does not explain when to choose this over related siblings such as cotlet_app_guide or timely_book_appointment, nor what preconditions (e.g., an open browser session) are required.

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