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

Annotations already declare non-read-only, non-idempotent, non-destructive. The description adds real behavioral context beyond them: server-side validation of workspace event names against their definition, plan-tier limits (100/1,000 event types) and the specific 403 plan_required error. It omits that retrying the same payload creates duplicate events, which is relevant for a non-idempotent write.

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?

Three dense sentences, front-loaded with the core action and the type taxonomy before plan constraints. No filler, though the plan-tier sentence could be compressed by dropping the numeric split if it is not decision-relevant.

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?

No output schema, so the description could mention what a successful send returns (event id / accepted status), but for a fire-and-forget ingestion endpoint the essentials — format, validation, attribution, plan gating — are all present. An agent can call this correctly from the description plus schema.

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 coverage is 100%, so the baseline is 3. The description still adds value: it clarifies that attribution to a contact is optional and can be done via either email or contact_id, and reinforces that `properties` is unconstrained for custom events — semantics the schema states minimally.

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+resource (record an event) and immediately splits it into the two distinct shapes: workspace-defined 'w:<name>' validated against its definition, and custom 'c:<name>' with arbitrary JSON. This distinguishes it from create-workspace-event and list-events without the agent needing to open any schema.

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 'w:<name>' branch implicitly tells the agent a workspace event definition must already exist, and the plan-tier sentence names the exact failure condition (403 plan_required). It does not, however, contrast this tool with trigger-automation or explain when to prefer a custom vs workspace event beyond format.

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