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

Annotations already declare this is a non-destructive, open-world read, so the description doesn't need to carry the safety profile. It adds the useful detail that results are day-level availability rather than concrete slots, but says nothing about pagination behavior when using timeframe (noted only in the schema) or result volume.

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?

A single front-loaded sentence that opens with what is returned and follows with the required input combinations, with no filler. The trailing 'GET /scheduling/available-dates' is marginal value for an agent that already has the endpoint, but costs little.

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 12 parameters and no output schema, the description covers the two principal calling patterns but omits the optional filters (user_ids, order_id, order_item_ids) and pagination semantics, which the schema and its per-field notes must supply. Adequate for a correct call, but not fully self-contained.

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 already 100%, so the baseline would be 3, but the description adds genuine cross-parameter logic the schema leaves implicit: a date range or timeframe, plus either appointment_id or duration + interval. That conditional pairing is the main thing an agent could get wrong, and it is stated explicitly.

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 ('Days that still have availability') and ties it to the scheduling endpoint, which is clearly distinguishable from sibling tools like aryeo_list_available_timeslots. It doesn't explicitly name that nearest sibling, so the day-vs-timeslot distinction must be inferred from the word 'Days'.

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 frames the use case ('for a proposed or existing appointment'), which implicitly tells the agent when this applies, and the parameter combos hint at the two workflows. However, it never states when to use aryeo_list_available_timeslots instead, nor any prerequisites beyond timezone being required by the schema.

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