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

Annotations already declare read-only, idempotent, non-destructive behavior, so the description does not need to repeat that. It adds meaningful context beyond annotations: default fields cannot be created or deleted, path forms are unsupported, and event_id must come from search_events. Return values are covered by the output schema, so no gap there.

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 front-loaded with the core purpose, then proceeds through prerequisites, constraints, and edge cases. All five sentences carry useful information, though it could be slightly tighter by combining the event_id prerequisite with the opening sentence.

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 read tool with multiple actions and an output schema, the description covers purpose, key prerequisites, default-field constraints, unsupported path forms, and where event_id comes from. It does not detail what each action returns, but the presence of an output schema fills that gap, making the definition complete enough 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 baseline is 3. The description mentions 'Dispatch via action' and repeats that `event_id` must be the event UUID from search_events, which duplicates the schema. It does not add explanation for the `field_kind` or `field_id` parameters, so it adds little 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?

The description clearly states a specific verb and resource: 'Read the provided event's default registration form.' It distinguishes behavior from creation tools by noting default fields cannot be created or deleted and must be hidden via update_default_user_field. It does not explicitly contrast with other read siblings, but the resource is unique enough to be clear.

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?

Provides actionable guidance: use `get_registration_form_metadata` before creating fields to match standard profile fields, and use `update_default_user_field` to hide default fields. It also warns that path forms return an unsupported message. It stops short of a full when-to-use-vs-alternatives map, but covers key prerequisites and exclusions.

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