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

Annotations already establish read-only, non-destructive, closed-world behavior, and the description adds genuine value beyond them: it enumerates what each delivery contains (event, timestamp, arrival, HTTP status, latency, attempt number, short failure reason) and, importantly, states what is NOT returned (payload, endpoint response body). Not stated: that results are capped/truncated and there is no pagination cursor, which matters given 'latest deliveries'.

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 sentences, front-loaded with the usage trigger before the return description, then closing with the negative routing. The middle sentence is dense but each item is a distinct fact. Minor cost: the return-field enumeration is a long comma list that could be trimmed.

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?

With no output schema, the description carries the burden of describing return values and does so concretely, including the explicit absence of payload and response body. For a two-parameter read tool, an agent has everything needed to call it correctly and set expectations.

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 both parameters are documented by the schema itself, including that the limit defaults to 20. The description does not add syntax or behavior for the webhook identifier beyond what the schema says (id from list_webhooks or name). Baseline 3 applies since the schema does the work here.

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?

Names a specific verb and resource (list a webhook's deliveries) and immediately states the scope: latest deliveries, newest first, for one webhook. It also clearly distinguishes itself from list_webhooks (all webhooks) and retry_webhook_delivery (resend), so an agent can route without opening a 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?

Gives an explicit triggering situation ('user asks whether a webhook or chat channel got a particular alert, why one is failing, or what was sent') plus two explicit exclusions naming the correct siblings. Nothing is left to inference about when to call this versus alternatives.

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