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

Even though annotations already declare destructiveHint=true and idempotentHint=false, the description adds substantial behavioral detail beyond the structured metadata: webhook delivery is HMAC-signed, the register response includes a secret that must be saved, the first evaluation silently initializes the watermark, five consecutive delivery failures auto-disable the intent, and evaluation happens roughly every 2 hours. This level of transparency is well above what annotations alone provide.

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 long but every clause earns its place given the tool's complexity: mechanics, security, filtering semantics, failure behavior, cadence, exclusions, and an example. The core purpose is front-loaded in the first line, and the exclusions are placed at the end where they complement the guidance rather than obscure it.

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 tool with seven parameters, no required fields, and an output schema, the description is remarkably complete. It explains the registration lifecycle, signature verification, watermark behavior, delivery failure handling, supported kinds, and the exact return shape ({intent_id, secret}). An agent has everything needed to register, list, and delete intents correctly without external docs.

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%, but the description meaningfully amplifies every parameter: it explains the action enum with defaults, maps each kind to its watch parameters, adds the critical constraint that webhook_url must be public HTTPS only with private hosts rejected, and clarifies intent_id's role in delete. This goes well beyond the schema's terse property descriptions.

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 precise verb+resource: 'STANDING QUERIES with webhook push — register an intent once and DC Hub POSTs an HMAC-signed webhook to YOUR https URL whenever matches grow.' This clearly differentiates it from one-shot tools like get_news and from email-based alerts like set_market_alert, so an agent can confidently identify what this tool uniquely does.

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 gives explicit when-to-use guidance: push notifications for recurring match detection, plus explicit exclusions: 'Do NOT use for one-shot reads (use get_news / list_transactions) or email alerts (use set_market_alert); this is machine-to-machine push.' It also provides a concrete invocation example, making the usage context unmistakable.

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