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

With no annotations, the description carries the full burden of behavioral disclosure. It reveals that notifications are signed POSTs, that a cron evaluates active subscriptions, the exact payload format, a 30-day paid window, and that payment is required ($0.01) with payment instructions returned. This is substantial transparency, though it doesn't cover failure modes or what happens after payment is made.

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 well-structured and front-loaded with the core purpose, followed by key details (payload, use case, payment). Every sentence adds value, and the length is appropriate for a tool with no annotations and no output schema. It avoids redundancy and is easy to scan.

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 the tool has 6 parameters and no output schema, the description provides a strong contextual picture: what it does, when to use it, how it works (cron, payload), cost, and what to expect in return (payment instructions). It doesn't detail the full payment flow or what happens after payment, but it covers the essential operational aspects for an agent to select and invoke the tool.

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%, so the baseline is 3. The description reinforces some schema terms (e.g., 'score delta' relating to threshold_score, 'tier change' relating to threshold_tier_change) and mentions the default 30-day window, but it doesn't add significant meaning beyond the schema's parameter descriptions. It doesn't mention max_notifications or duration_days explicitly, but those are already well-described in the schema.

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 clearly states the tool's function: subscribing a webhook URL to receive signed POST notifications on reputation drift. It names the specific resource (reputation snapshot drift) and differentiates from sibling tools like subscribe_attestation_freshness by focusing on reputation drift rather than attestation freshness. The explicit phrase 'replaces polling /cross-chain-reputation' further clarifies its distinct purpose.

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 provides a clear use case: 'Use to be notified the moment a counterparty's reputation degrades' and names an alternative (polling /cross-chain-reputation). It does not explicitly state when not to use the tool, but the context is sufficient for an agent to understand when it is appropriate. The mention of a paid window ($0.01) also signals a cost consideration that should inform usage.

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