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

Annotations only declare readOnlyHint=false, destructiveHint=false, openWorldHint=true. The description goes beyond them by disclosing the exact side-effect profile ('sends nothing to the client and reaches no one, so it runs without asking first'), the return value (client_id) and where it is used, plus the auth requirement (user's Cotlet API key with access to this app).

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 scoping and safety facts are front-loaded well, but the no-notification point is stated twice ('Nothing is sent to the client' and 'It sends nothing to the client and reaches no one'), and the opening line restates the title. Slightly wasteful rather than bloated.

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?

With no output schema, the description correctly compensates by explaining the return value (client_id) and its consumer, and it covers auth, side effects, and dedupe guidance. Nothing an agent needs to call this correctly is missing.

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?

Schema description coverage is 100%, so first_name, last_name, email and phone are already documented with types and required-ness. The description adds no format or constraint detail for these fields (e.g. phone country-code handling), so the baseline 3 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?

The description uses a specific verb+resource ('Create a client profile') and distinguishes itself from siblings by naming list_clients (search) and create_appointment (downstream consumer of the returned client_id). An agent can place this tool precisely within the Fresha client workflow.

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 states the precondition ('Search with list_clients first to avoid a duplicate profile') and the downstream step ('pass to create_appointment'), giving explicit routing to alternatives and sequencing. Nothing about when to reach for this tool is left to inference.

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