update_event_ref

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

Annotations already declare the safety profile (readOnly=false, destructive=true, idempotent=true), so the bar is lower. The description usefully clarifies the operation is scoped to the person's reference rather than the shared event itself ('a person's reference to a shared event'), implying other sharers are unaffected, but it omits error/refusal behavior and the effect of the allow_new_type custom-type creation.

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 compact sentence with the verb and scope front-loaded and no filler. It is well-sized, though the two facets are tucked behind a colon rather than fully exploiting the space available for such a mutation tool.

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 5-parameter mutation tool the description is thin: it relies entirely on a 100%-covered schema and annotations for parameters and safety. There is no output schema and none is referenced, and no mention of return values or failure modes, leaving the agent to infer the result of the operation.

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 the schema already documents role, attributes, allow_new_type and their null semantics in detail. The description only restates role and attributes at a high level, adding no syntax, format, or edge-case meaning beyond what the schema provides; baseline 3 is appropriate.

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: changing a person's reference to a shared event, including the two facets it touches (role and attributes). The phrase 'in place' hints at in-place modification rather than creating a new reference, which subtly contrasts with add_event_ref, but the description never names that sibling or otherwise differentiates itself 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 implied rather than stated: an agent can infer this is the tool to reach for when an event reference already exists and needs modification, versus add_event_ref or cite_event. There is no explicit when-to-use/when-not guidance, no prerequisites, and no named alternatives.

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