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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false, so the safety profile is covered. The description adds real value beyond that: a hard cap of 100 records, the auth scope required, zero cost, and the guarantee that receiver failure does not lose operation or case state.

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 compact sentences, front-loaded with what is returned, followed by scope/cost and a failure guarantee. Every sentence earns its place and no wording is wasted.

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 simple parameterless read-only list tool with no output schema, the description supplies the record cap, the field list, the scope requirement, and the state-safety guarantee. It could be slightly more complete by noting ordering guarantees or retention, but nothing critical to correct invocation is missing.

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?

The tool takes zero parameters, so there is nothing for the description to clarify beyond the schema. Per the baseline for parameterless tools, a 4 is appropriate.

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 ('Inspect') and resource ('last 100 owned webhook delivery attempts') and enumerates the returned fields, so an agent can tell it is a read-only delivery-log tool. It does not explicitly name or contrast with any sibling (e.g., replay_event), so it falls short of the 5 level.

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 the precondition 'Requires webhooks scope; free,' which is useful context, but gives no when-to-use guidance, no exclusions, and does not point to any alternative sibling for related tasks. Usage is only implied by the description of returned content.

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