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

Annotations only declare readOnlyHint=false and idempotentHint=false. The description adds genuinely useful behavior beyond that: the delivered ping carries no payload, so the agent must call check_notifications to actually read notifications. That async contract is the key operational detail and it is disclosed. Auth requirements and what happens when an existing webhook is overwritten are not covered.

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?

Two sentences with no filler, and the conditional precondition is front-loaded before the mechanism. The 'ping carries no content' clause is placed immediately after, so the agent learns the follow-up requirement without digging.

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 one-parameter, no-output-schema tool with annotations covering the write/idempotency profile, the description supplies the usage condition, the delivery mechanism, and the required follow-up call. Only auth/ownership requirements and overwrite behavior are left unstated.

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% for the single url parameter, including the empty-string removal semantics, so the schema carries the burden. The description adds no format, length, or validation detail beyond it. Baseline 3 applies.

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 description conveys a specific outcome: register an https URL that receives a POST ping on new notifications, replacing polling. The verb 'set' is only implied by the name and the effect is stated rather than named, but the resource and scope are unambiguous. It distinguishes itself from the polling path, so an agent can tell it apart from check_notifications.

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?

'If you run as a service' gives a clear precondition for use, and the contrast with polling tells the agent when this is preferred over periodic fetching. It also names check_notifications as the follow-up path. There is no explicit when-not or cost caveat, but the selection context is solid.

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