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

Annotations already declare readOnlyHint=false, idempotentHint=false, openWorldHint=true and destructiveHint=false, so the safety profile is covered. The phrase 'bounded replay protection' adds a genuine behavioral trait beyond the annotations, but it is left undefined — the agent cannot tell whether this means a rate cap, a dedupe window, or a one-shot guard.

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?

A single front-loaded sentence with no filler. It is efficient, though the terseness is part of why the parameter and re-use semantics go unexplained.

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 gaps are narrower than they first appear. Still, for an open-world, non-idempotent mutation with two undocumented parameters, the description leaves an agent short of what it needs to invoke this confidently.

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 0%, so the description carries the full burden for both required parameters, yet it mentions neither subscriptionKey nor the format/meaning of eventKey. 'One stored webhook event' only loosely implies an event identifier and gives no hint about the subscription key's role.

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 plus resource: 'Replay one stored webhook event.' The word 'stored' and 'one' scope it precisely, distinguishing it from evidence_send_webhook_test (live test) and evidence_webhook_history (read). It doesn't explicitly name those siblings, but the operation is unmistakable.

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?

No when-to-use guidance and no alternatives named. With siblings like evidence_send_webhook_test and evidence_webhook_history in the same domain, an agent gets no signal about when replay is the right choice versus triggering a fresh test send or inspecting history.

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