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

Annotations already cover the safety profile (readOnly, non-destructive, closed-world), and the description goes well beyond them: cancelled-but-not-over events still answer with cancelled=true and no upcoming dates, scheduleChange distinguishes postponed/rescheduled/moved-online states, and managedBy is only populated when the organizer profile is public. This is exactly the behavioral context an agent needs before calling.

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 the one-line purpose, and every following sentence covers distinct return/behavior detail that no structured field provides. It is a dense run-on block rather than segmented, but with no output schema the length is earned rather than padded.

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 takes on the burden of explaining the payload and does so well (images/cover, owned, managedBy, cancelled, scheduleChange, previousStartDate, current vs former slug). It omits what happens on an unknown or unpublished slug (error vs empty), which is the one gap for a lookup tool.

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 0% for the single slug parameter, so the description must carry it, and it does add real meaning: a former slug (renamed year or town) resolves to the same event and the response returns the current slug. It does not describe slug format or case/encoding expectations, which is the only remaining gap.

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 ('Get one event by slug') and scopes it to 'one published event', which implicitly separates it from the list_* siblings. It never names an alternative such as get_not_listed_event or list_events, so the differentiation rests on the reader inferring scope from 'published'.

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?

There is no explicit when-to-use or when-not-to-use guidance and no alternative is named, even though the sibling list contains several closely related lookups (get_not_listed_event, similar_events, get_event_join_details). The 'published event' wording hints at scope but is not framed as a routing rule.

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