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

Annotations already indicate readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds useful behavioral context beyond annotations by specifying what the output contains and by warning that free-text fields are labeled as untrusted content, which is relevant for downstream handling.

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 is two sentences with no filler. The main function is front-loaded, the output contents are listed compactly, and the untrusted-content note is a meaningful addition that earns its place.

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?

There is no output schema, so the description correctly takes on the burden of describing return values: names, email addresses, and relationship labels. The event and contact context are clear, parameters are fully documented in the schema, and annotations cover the read-only/destructive profile. This is sufficient for an agent to invoke and interpret the tool correctly.

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 eventId, contactId, and org. The description does not add parameter-specific details beyond the schema, but it does not need to; the baseline of 3 is appropriate when structured parameter documentation is complete.

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 uses a specific verb ('List') and identifies a precise resource: a contact plus their associated people for one event, including names, email addresses, and relationship labels. This clearly distinguishes it from tools like get_contact, list_attendees, or search_contacts by adding the 'for one event' scope.

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 description establishes clear context: use this when you need a contact and their associated people for a specific event. It does not explicitly name alternatives or exclusions, but the event-scoped framing provides enough guidance to know when this tool is appropriate relative to broader or single-contact tools.

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