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

Annotations already declare readOnlyHint/idempotent/non-destructive, and the description adds the critical behavior the annotations cannot convey: it 'opens nothing by itself' and returns procedural guidance (screens, buttons, fields) that must then be executed via browser tools. It also states the external constraint — Fresha has no public API or developer docs — which explains the whole design and is consistent with openWorldHint=false.

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?

Front-loads the action and the surprising return behavior, and stays to three short sentences. Minor waste: the 'from ChatGPT, Claude or any AI agent' clause adds nothing, and 'Fresha's official API:' is a dangling fragment that should have been merged into the following clause.

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 guidance tool with no output schema, the description covers what it returns, what it does not do, and how to continue. The only gap is the shape of the returned instructions (free text vs. structured steps), which an agent might want to know before parsing.

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; the schema (empty object, additionalProperties false) is fully self-explanatory. Baseline of 4 applies.

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 specific verb and resource ('List clients in the user's own Fresha account') and then discloses the non-obvious truth that the tool returns step-by-step instructions rather than data. That disclosure is what makes the purpose usable, though the name still reads like a data-fetch tool and the description never contrasts it with the plain 'list_clients' sibling.

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 an explicit workflow: call this, then perform the action with the cotlet_browser_* tools in the Fresha Cloud Browser. It also explains why (no public API, no developer docs), which implicitly rules out an API path. It stops short of naming when to prefer a sibling tool instead.

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