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

Annotations already declare readOnlyHint=true, openWorldHint=true and destructiveHint=false. The description adds real value beyond that: return ordering (start order), coverage (past and future), the fact that cancelled appointments are removed and not returned, the per-person calendar permission requirement, and the Cotlet API key/auth prerequisite.

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 and scope, then behavioral facts, then auth. Efficient overall, though the final API-key sentence is slightly boilerplate and could be trimmed.

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 read-only list tool with full schema coverage and no output schema, the description supplies the ordering, cancellation semantics, cross-calendar permission, and auth context an agent needs. Little is missing; it just lacks explicit sibling routing.

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% and the schema already documents all three parameters, including defaults ('Default: same as from', 'Default: you') and the source for provider_id ('from list_services'). The description adds no parameter-level 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 (list appointments) with clear scope: a date range, returned in start order, past and future. It doesn't explicitly name a sibling like get_appointment or find_open_slots for differentiation, so it falls short of the top tier.

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?

Usage is implied through the date-range framing and the note that another team member's calendar requires a permission, but no explicit when-to-use vs. alternatives guidance is given. It doesn't contrast with get_appointment or find_open_slots.

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