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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so safety is covered. The description usefully confirms the read semantics with 'open booking slots' but says nothing about how the required durationMinutes shapes the result set, whether results are timezone-adjusted, or whether an expert can return zero slots.

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 clause with no filler, which is the right shape. It is slightly too terse for a three-required-parameter tool, leaving no room for the usage and parameter context that would be more valuable than the whitespace.

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?

No output schema, so the description must convey what a 'slot' is (start/end time, timezone, price, expert-side metadata) and does not. Combined with an unexplained durationMinutes and no booking-flow context, an agent cannot confidently call this or interpret the result.

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 description coverage is 0%, so the description carries the full burden. It explains date as YYYY-MM-DD (already enforced by the schema pattern) and implies expertId, but the third required parameter, durationMinutes (5-180), is never mentioned, and its likely role in filtering slots is left undocumented.

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: returns open booking slots for a given expert and date. It does not distinguish itself from neighbours such as get_expert, check_expert_online, or set_availability, so the agent must infer it is the read side of the availability pair.

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?

No when-to-use guidance, no prerequisites, and no mention of the obvious downstream sibling create_booking. The agent is left to guess whether this must be called before booking or whether create_booking validates slots itself.

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