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

Goes beyond annotations by disclosing the external side effect ('reaches people outside your account'), the default confirmation requirement and its toggle, the auth prerequisite (Cotlet API key with app access), and the return value (count of clients alerted). This is rich behavioral context for a write tool.

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-loaded with purpose, but the confirmation instruction is stated twice ('By default you confirm each call... you can switch that off' and 'Reaches other people: confirm with the user before each call'), which is redundant padding.

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 3-param write tool with no output schema, the description covers purpose, external effect, confirmation policy, auth requirement, and return value. Nothing essential to correct invocation 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 coverage is 100%, so the schema already documents waitlist_entry_ids, start, and provider_id. The description adds only loose framing ('entries you pick', 'an open slot') without format or disambiguation detail, so the baseline 3 is correct.

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 ('Alert chosen waitlisted clients about an opening') and adds the mechanism ('Offers an open slot to the waitlist entries you pick'), which distinguishes it from vagaro_add_to_waitlist and vagaro_list_waitlist. It doesn't explicitly name those siblings, so it falls short of a 5.

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 clear operating context: by default each call is confirmed, this can be switched off, and the recipient set is external so the user should confirm. It stops short of naming alternatives like vagaro_add_to_waitlist for related cases.

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