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

With no annotations, the description carries the full burden. It discloses payment requirements (API key or per-call fee), event types, delivery duration (7 days), extension behavior, and that deliveries are signed. It does not explicitly state that this creates/changes a subscription, but the title and extension mention imply state change. Overall, it adds substantial behavioral context beyond the schema.

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?

The description is a single dense paragraph, leading with payment details rather than the primary purpose. It contains useful information but lacks front-loading and scannable structure. The sentence 'Requires a ChainHelix API key as bearer token, or 70 cents...' is complex and sits before the actual functionality, making the intent less immediately apparent.

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?

Given only two parameters, no annotations, and an output schema, the description covers cost, authentication, event semantics, delivery duration, extension, and signature verification. Missing details like error cases or how to unregister might be relevant, but sibling tools cover unregister. For a registration tool, this is reasonably complete.

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 schema has 'url' and 'events' with no descriptions (0% schema coverage). The description explains 'url' must be an https URL and defines the two event enum values. However, it does not clarify that 'events' is optional or how the system behaves if omitted (e.g., default to both events). This partial compensation leaves ambiguity about the events parameter.

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 the core action—'Get ChainHelix events PUSHED to your https URL instead of polling'—which implies registering a webhook. It names specific event types (signal_sealed, trade_closed). However, it lacks an explicit verb like 'register' or 'subscribe' and does not clearly differentiate from sibling tools like webhook_status or webhook_unregister.

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?

The phrase 'instead of polling' gives a clear scenario for using push, and 'call again with the same URL any time to extend' is a usage tip. There are no exclusions, prerequisites beyond authentication/cost, or comparisons to alternative tools provided.

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