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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is fully covered. The description adds the lookup relationship (event type -> schedule it uses), but says nothing about behavior on an unknown slug or whether the full schedule configuration is returned. Useful but thin given annotations carry most of the weight.

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 sentence with zero filler, front-loaded on the verb and the resource. Nothing is buried and nothing needs to be skimmed past.

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 one-parameter read with full annotations and no nested objects, the description supplies enough for correct invocation. The remaining gap is scope: without an output schema, a phrase on what the schedule payload contains (or that it is the same shape as get_schedule) would remove the last ambiguity.

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 is the only place param meaning appears, and it does identify eventSlug as the slug of one of the user's event types. It gives no format guidance (e.g., whether the slug excludes the username prefix) or validity constraints, so the 0% coverage gap is only partially closed for this single parameter.

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 (fetch) and a precisely scoped resource: the availability schedule an event type uses, reached by slug. That phrasing implicitly separates it from get_schedule (by id/key), get_schedule_by_user, and get_default_schedule, though none of those siblings are named explicitly.

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 only implied: an agent infers it should call this when it has an event slug and needs the attached schedule. There is no explicit when-to-use, no exclusion, and no pointer to get_schedule or get_schedule_by_user as the alternative when an id rather than a slug is in hand.

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