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

Annotations already declare readOnly/openWorld/destructive=false, so the safety profile is covered. The description adds genuinely useful non-annotation context: the price caveat ('menu prices shown in Vagaro') and the auth requirement ('needs the 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?

Front-loaded and compact, but the first two sentences are near-duplicates ('duration, price and who performs each service' vs 'duration, price and the providers who perform them'), spending words without adding information. Minor redundancy only.

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 carries the return-value burden and does so adequately (services, duration, price, providers), plus auth needs. A single optional param with full schema coverage keeps the remaining surface small, so the definition is nearly complete for what an agent needs.

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?

Only one parameter with 100% schema coverage; the schema already documents location_id, its source (list_locations) and the default. The description hints at single-location scoping ('one location') but adds no format or syntax detail beyond the schema, 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?

States a specific verb+resource ('Service menu of a location') and enumerates what the returned services contain (duration, price, providers). An agent can distinguish this from vagaro_list_locations or vagaro_list_appointments without opening the schema.

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 downstream context: 'Use service_id in search_availability and book_appointment,' routing the agent through the booking workflow. It stops short of explicit when-not-to-use guidance or naming an alternative service-listing tool, so it is not a full 5.

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