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

Annotations already declare write/destructive/idempotent/openWorld, so the bar is lower, and the description still adds real value by warning that setting a status "can trigger Evenium's own workflows" — a side effect not encoded in the annotations. It does not spell out that the previous status is overwritten or that triggered workflows may notify guests, which would be the next useful detail.

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?

Three short sentences, front-loaded with the WRITE marker, then the safety prerequisite, then the endpoint. No filler or repetition.

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 3-parameter mutation with annotations covering the safety profile and no output schema, the description covers what it does, the prerequisite read, and the workflow side effect. Missing only the irreversibility/overwrite consequence, which matters given destructiveHint=true.

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 67% and the schema already documents event_id/contact_id formats and the full status enum. The description's status examples (CONFIRMED, DECLINED, CANCELED) largely restate the enum rather than adding new meaning, so it neither compensates for the gap nor adds much beyond the schema.

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?

"WRITE: set the registration status of a guest at an event" is a specific verb+resource with concrete enum examples and the underlying endpoint. It clearly separates this from the read path (evenium_get_guest_status), but does not disambiguate against the very similar sibling evenium_update_guest_post_status, which an agent could easily confuse it with.

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?

Explicitly tells the agent to read the current value first with evenium_get_guest_status, which is a concrete prerequisite and names the alternative read tool. It stops short of stating when *not* to use this tool or when the post-status variant is preferred.

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