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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds real value with the platform-availability restriction and the return-field list, but says nothing about empty/missing-result behavior or pagination.

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?

The payload is front-loaded: what is returned, then the availability caveat, then the underlying endpoint. Two compact sentences and a path line, none of which is redundant, though the endpoint line adds little for an agent that already has the parameter names.

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 only two required, fully documented parameters, a read-only annotation set, and no output schema, the description covers the essential gaps by listing the returned fields and the platform restriction. Only the edge-case behavior (no booking present) is unaddressed, which is minor here.

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 100%, so both parameters (event_id, contact_id) are fully documented in the schema, including the `ext:` id forms. The description only restates the event/guest scoping and adds no syntax or format detail beyond that, which is the expected baseline.

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?

The description names the specific resource ('hotel room bookings of one guest at an event') and enumerates the fields returned (room id, check-in/check-out, status), so the agent knows exactly what data comes back. It is distinguishable from siblings like evenium_list_hotels and evenium_get_guest by being guest-and-event scoped.

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: fetch accommodations for a known guest within a known event. The one explicit constraint, 'Not available on the evenium.net platform,' is a useful eligibility caveat but not a when-to-use rule. No sibling alternative (e.g. list_hotels for hotel inventory) is named or excluded.

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