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

Annotations already declare readOnly and non-destructive, so the safety bar is met, but the description adds genuine value by disclosing the return format (step-by-step screens, buttons, fields) and the crucial fact that it "opens nothing by itself." That clarifies the tool produces instructions rather than data or side effects. It stops short of describing prerequisites or how the guide relates to a connected account.

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 behavior is front-loaded, but the definition carries noise: "from ChatGPT, Claude or any AI agent" is marketing padding, and the closing line about an official REST API "(checked 6 Nov 2026)" is irrelevant to invoking this tool and somewhat confusing.

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?

Given zero parameters, no output schema, and annotations covering the safety profile, the description is largely complete: it states the guide return format and the browser follow-up. The only minor gap is it doesn't address prerequisites such as whether an Intervals.icu account must already be connected.

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 and the schema is trivially complete, so the baseline is a 4. The description doesn't need to add parameter meaning here, and it doesn't invent any.

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 ("List activities in the user's own Intervals.icu account"), but then recasts the tool as one that "Returns how to do it in Intervals.icu step by step" and "opens nothing by itself." That tension between the listing name and the actual guide-returning behavior leaves the purpose understandable but muddy, and it doesn't differentiate itself from sibling list tools.

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 downstream workflow ("then do it with the cotlet_browser_* tools in the user's Intervals.icu Cloud Browser"), which is helpful context. It does not say when to choose this tool over alternatives like intervals_icu_list_wellness or the browser guides, so the selection guidance remains implied.

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