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

Annotations already declare non-readOnly, non-idempotent and non-destructive, and the description goes well beyond them: it states the payload is re-signed afresh, that normal retries still apply, that the original delivery record is left intact, and that a rate limit of 30/min applies. Those are the operational facts an agent needs before firing a write that cannot be safely repeated.

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, front-loaded with the effect of the call and followed by side effects and constraints. No filler, no restatement of the title.

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?

An output schema exists, so return values need no prose. For a two-parameter mutation it covers the effect, the non-destructiveness, retry behavior, the precondition, and the rate limit, leaving nothing material for an agent to guess.

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 both 'id' and 'webhook_id' are already documented in the schema, and the description adds no field-level detail such as format or where the delivery id is obtained. Baseline 3 is appropriate because the schema carries this burden.

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 verb+resource are concrete ('Send a delivery again') and the description immediately disambiguates what 'resend' means: same payload, new signature, original untouched. It clearly separates this mutation from the read-side siblings like get_webhook_delivery and list_webhook_deliveries, though it never names an alternative explicitly.

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?

Gives a hard precondition ('The endpoint must be turned on') and a throughput ceiling ('limited to 30 resends a minute'), which is actionable before-call guidance. It stops short of stating when not to use this versus send_test_webhook_event or how to recover from a rejection, so it is not a full when/when-not/alternatives set.

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