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 the returned field set and the REST path, but says nothing about pagination semantics, result caps, permissions, or ordering beyond what the schema already encodes.

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?

Two compact sentences lead with what is returned and follow with the filters, then a terse endpoint reference. Nothing is wasted, though the raw path adds little for an agent that already has the tool bound to that endpoint.

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 usefully enumerates the returned fields (name, email, company, status values, category, fields), which is the main gap it needed to fill. Remaining gaps are minor: no explicit pagination/next_first_result narrative and no sibling routing, both of which are partly recoverable from the schema.

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 every parameter is already documented with its own semantics. The description reinforces the filterable dimensions but adds no syntax or format detail beyond the schema, and its generic 'name' filter glosses over the separate first_name/last_name parameters. Baseline 3 applies.

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 ('List the guests (invited contacts) of an event') and enumerates the returned fields plus the underlying endpoint. It is clearly distinguishable from the single-record siblings like evenium_get_guest, but it never explicitly contrasts with the nearby evenium_list_contacts or evenium_list_event_part_registrations.

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?

The filter list ('Filter by status, name, email, company or last update') implies how to narrow results, but there is no statement of when to prefer this over evenium_list_contacts or evenium_get_guest, and no prerequisites or exclusions are given.

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