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

Beyond the annotations (readOnly/openWorld/idempotent), it discloses that a real outbound request is made, how it is signed (current secret plus previous one during the 24h rotation window, two `sig=` values, accept if ANY matches), the exact return shape, the error enumeration (timeout | network | ssrf_refused | ...), and that nothing is queued, retried or stored. That is materially more than the structured fields convey.

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?

Front-loaded with the action and the id source, then the signing and return details in descending priority. Dense parentheticals (signature semantics, error codes) are justified because there is no output schema, though the single long paragraph is heavier than strictly necessary.

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 and only one parameter, the description carries the burden of explaining the response — which it does precisely ({ok, channel_id, test} with {ok, status} or an error string) — plus the signing edge case during rotation. Nothing an agent needs to call or interpret this correctly 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?

Schema coverage is 100% and the single parameter is already documented, so the baseline is 3; the description adds value by pointing to alerts_list_channels as the authoritative id source and framing it as the channel to re-deliver to. No format details beyond that, hence not a 5.

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 and resource — 'Send the signed `test` event to one of the user's webhook channels again' — which cleanly separates it from alerts_register_webhook, alerts_rotate_webhook_secret and the sibling resend_delivery (real vs. test delivery). An agent can identify the operation without opening the 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 a concrete trigger ('for example after the receiver installed a new secret from alerts_register_webhook or alerts_rotate_webhook_secret') and names alerts_list_channels as the id source. It stops short of an explicit exclusion against alerts_resend_delivery, so the test-vs-real distinction must be inferred from 'test' event wording.

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