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

Beyond the readOnly/idempotent/non-destructive annotations, the description discloses the crucial non-obvious trait: this tool performs no mutation itself and only returns procedural steps, so the agent must know to chain into the browser tools. The final sentence about the absence of an official API is context but adds little behavioral information.

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?

Two dense sentences plus a meta-note carry the whole definition, and the no-side-effects behavior is front-loaded in sentence two. The no-public-API digression and the marketing-style 'from ChatGPT, Claude or any AI agent' phrase could be cut without loss.

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?

Return values are described ('screens, buttons, fields'), which is necessary since there is no output schema, and the dependency on the cotlet_browser_* tools is stated. What remains unexplained is how a zero-argument tool scopes the measurement (which metric, which value) and how the returned guide is consumed end-to-end.

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 the baseline applies; the schema is empty and fully described. The description does not mention, however, how a parameterless tool determines which measurement is being logged, which is a mild gap.

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 second sentence clarifies the real behavior: it returns step-by-step instructions for logging a measurement and opens nothing itself. However, the leading sentence 'Log measurement in the user's own Fitatu account' restates the title and suggests an action the tool does not perform, and nothing distinguishes it from siblings like fitatu_log_food or fitatu_log_quick_entry.

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 usable two-step workflow — get the guide here, then execute with cotlet_browser_* tools — which is real guidance. It does not say when to prefer this over other fitatu_log_* tools or what to do if the user has no Cloud Browser session open.

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