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

Annotations already declare read-only and non-destructive behavior, and the description adds useful context: role encoding, checked_at null semantics, anonymous/deleted placeholder emails, omitted personal app link, and filter-after-read behavior. It does not cover auth or rate limits, but it adds substantial behavioral detail beyond annotations.

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 description front-loads what is returned, then packs role codes and data caveats into a few dense sentences with no filler. The endpoint reference at the end is compact and useful.

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 carries the return-value burden and does list key fields and quirks, plus pagination guidance. It could be stronger by specifying pagination metadata like next_offset or sort order, but it is sufficient for correct invocation.

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 parameters are already well documented in the schema. The description adds some context around pagination and response role codes, but little parameter-specific detail beyond what the schema provides.

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 that it returns event participants and enumerates the included data fields and role codes, making the resource specific. It does not explicitly distinguish itself from siblings such as eventee_list_registrations or eventee_list_groups.

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?

Offers pagination guidance for large events and explains that filters apply after the full list is read. However, it does not say when to use this tool instead of related listing tools or mention preconditions.

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