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

Annotations already declare readOnlyHint=false, idempotentHint=true and destructiveHint=false, so safety is largely covered. The description earns credit for adding non-obvious behavior: `properties` replaces the entire list rather than merging, and already-recorded events are unaffected. It does not disclose the return value or whether the replacement is reversible, which matters since annotations label this non-destructive despite a replace-all semantic.

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 short sentences, no filler, and the headline purpose is front-loaded ahead of the two caveats. Every clause carries information an agent cannot get from the schema or annotations.

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?

Annotations cover the safety profile and there is no output schema to explain, so the remaining burden is small but not fully met: it is unclear whether omitted fields are left untouched (partial update) or cleared, which is the single most important ambiguity for an update tool. Adding one sentence on that and on failure behavior for a missing/invalid id would close the gap.

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 only 20%, so the description must carry the load, and it does so for exactly one parameter: it explains that `properties` is a full replacement, not an append/merge. The other parameters (name, title, description, and the id format) get no added meaning from the description; `id` is partly covered by the schema's etp_xxx/name/w:name note, but the update-vs-omit semantics of the scalar fields are left unstated.

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?

Specific verb+resource ("Update a workspace event definition") that maps cleanly onto update-workspace-event and is distinguishable from the get-/list-/create-/delete-workspace-event siblings by prefix. It stops short of explicitly naming a sibling or the object it operates on for an agent unfamiliar with the domain.

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?

Usage is only implied: the tool is for editing an existing event *definition*, and "Stored events are not changed" signals the scope boundary between definition and instance. There is no explicit when-to-use, no prerequisites (e.g. that the definition must already exist, use create-workspace-event otherwise), and no mention of delete-workspace-event for removal.

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