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

With no annotations provided, the description carries the full burden of disclosing side effects. It states that a webhook is registered, that it fires on changes (not continuously), and that cadence can be throttled to hourly or nyse_open. This is meaningful behavioral context beyond a simple 'subscribes to scan.' It stops short of explaining webhook payloads, unsubscription, or authentication requirements, but it does cover the key behavioral triggers and delivery options.

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 three sentences long, with the main purpose in the first sentence, delivery details in the second, and cadence/use-case in the third. Every sentence contributes distinct information, and the formatting makes it easy to scan. No filler or redundant repetition.

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?

The tool has 8 parameters and no output schema, so the description should explain what happens after subscription (e.g., response containing a webhook ID) and the shape of webhook deliveries. It does not describe the payload format, how to manage/delete the subscription, or the mobile_push channel mentioned in the schema. While the main use case is covered, these gaps prevent a higher score.

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 100% coverage, so the baseline is 3. The description adds minor value by restating delivery patterns (e.g., 'Pass target_url for an https POST, or channel:'discord' + discord_url') and default cadence, but these are already fully documented in the input schema. No new parameter-level insight is provided beyond what the schema already offers.

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 opens with a specific verb+resource: 'Register a webhook that fires when matches for a scan query change.' This clearly distinguishes the tool from siblings like tickerbot_subscribe_ticker or tickerbot_subscribe_signal, which target different event types. The intended use case is also stated, leaving no ambiguity about what the tool accomplishes.

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 description explicitly says 'Use to satisfy "alert me when this happens" prompts,' giving a clear trigger for adoption. It also explains delivery-mode alternatives (target_url, Discord, in-app) and cadence options. However, it doesn't explicitly contrast with sibling subscribe tools, though the 'scan query change' context implicitly differentiates it.

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