Register for event

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

No annotations are provided, so the description carries the full burden. It discloses a behavioral requirement (the environment variable for writes), but does not describe side effects, error handling, or response format. This is adequate but not comprehensive.

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 sentences that are both concise and front-loaded. The first sentence states the core purpose, the second gives a critical usage condition. No redundant words or fluff.

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 6 parameters, 2 required, no output schema, and no annotations, the description is too minimal. It does not cover return values, error conditions, or behavior for optional parameters. A write operation requires more context to ensure correct use.

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 50%, and the tool description adds no additional meaning to parameters. It does not explain the purpose or constraints of the 6 parameters (e.g., contact_id, event_id) beyond the schema's limited descriptions. The description should compensate but does not.

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 clearly states the action ('Create a Participant record') and the context ('registering a contact for an event'). It uses a specific verb and resource, distinguishing it from sibling tools like civicrm_create_contact or civicrm_add_to_group. This is a clear, unambiguous purpose.

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 includes a clear prerequisite ('Requires CIVICRM_ALLOW_WRITES=true'), which guides usage. It does not explicitly state when not to use or compare with alternatives, but the context of registration is distinct enough for an agent to differentiate. Lacks explicit exclusions.

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