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

With no annotations, the description carries the transparency burden. It discloses the trigger behavior (fires on condition match), delivery methods (POST/Discord/in-app), and gives a realistic condition example. It doesn't cover edge cases like validation or idempotency, but the core behavior is well described.

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, front-loaded with purpose, followed by practical usage details and an example. Every sentence earns its place without redundancy.

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?

Despite 8 parameters and no output schema, the description provides enough context to select and invoke the tool correctly. It highlights the most complex parameter (condition) and the channel configuration interplay. Return values are not specified but can be inferred for a subscription creation 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 covers all 8 parameters with descriptions, so baseline is 3. The description adds value by explaining relationships between channel, target_url, discord_url, and provides an example of the `condition` parameter, going beyond 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?

Clearly states it registers a webhook for one ticker that fires when a condition matches, with a concrete SQL clause example. This distinguishes it from broader sibling tools like subscribe_scan or subscribe_events.

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?

Provides explicit guidance for delivery channels (target_url for HTTPS POST, discord_url for Discord, omit for in-app) and clarifies the condition format. It doesn't explicitly name alternative tools or exclusions, but the single-ticker scope is clear.

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