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

Annotations already declare idempotentHint=false and destructiveHint=false, but the description adds the consequence ('calling it twice creates two contacts') and the important side-effect disclosure that no message is sent to the contact. The POST /contacts endpoint adds further operational context.

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?

Three short sentences, front-loaded with the write operation and non-idempotency warning, then the dedupe instruction, then the no-notification note. Nothing is padded.

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 14-parameter mutation with no output schema and no annotations about the response, the description omits what comes back (e.g. the new contact ID needed for follow-up calls) and gives no guidance on which fields are meaningful despite none being required. The safety and dedupe story is complete; the parameter and return story is not.

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?

14 parameters with only 7% schema description coverage, and the description mentions no field semantics at all — it does not clarify that zero parameters are required, nor which fields (email, first_name, last_name) identify a contact. The schema does supply types and constraints, but the description makes no attempt to compensate for the coverage 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?

States a specific verb and resource ('create ONE new contact (guest/customer) in Bookingmood') and implicitly scopes it against the get/list/update_contact siblings by insisting on a single new record. The 'WRITE' prefix and endpoint signal make the operation unmistakable.

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?

Explicitly directs the agent to search with bookingmood_list_contacts first to avoid duplicates, which is a concrete when-to-use precondition and names a sibling tool. It stops short of stating when not to use it (e.g. when a contact already exists, use bookingmood_update_contact), but the dedupe guidance is strong.

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