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

The annotations already declare readOnlyHint=true and idempotentHint=true, and the description usefully confirms this by saying it 'opens nothing by itself' – pre-empting the natural assumption that a 'Book appointment' tool mutates data. It also discloses that Portrait Care has no public API, developer docs, or Zapier app, which explains why browser automation is the only path; the quote and the check date are extra detail but the underlying signal is genuinely useful.

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 and the 'opens nothing by itself' caveat are front-loaded in the first two sentences, ahead of the follow-up-tool instruction. The third sentence carries a lengthy quoted phrase and a check date that could be trimmed without losing meaning.

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 tool with no output schema, the description covers what comes back (step-by-step screens, buttons, fields), what it does not do (open anything), and what to do next. That is sufficient for an agent to call it correctly; only explicit differentiation from the other Portrait Care and cotlet_app_guide siblings is absent.

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 and the schema-driven baseline applies. No parameter guidance is missing because no inputs exist.

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 names a specific resource and outcome: it returns step-by-step instructions (screens, buttons, fields) for booking a Portrait Care appointment. It also implicitly routes execution elsewhere by naming the cotlet_browser_* tools, though it never names the closest sibling, cotlet_app_guide, or contrasts itself with portrait_care_reschedule_appointment.

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 clearly states the use case (booking in the user's own account) and the immediate follow-up action (perform the steps with cotlet_browser_* tools), which is actionable guidance. It stops short of explicit exclusions, so an agent is not told when to prefer cotlet_app_guide or when to use reschedule instead.

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