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

Annotations declare no safety hints (readOnlyHint=false, etc.), but the description adds important behavioral context beyond those annotations: the endpoint is temporary (one hour lifetime), it returns a public URL, expiration timestamp, and request count. It also notes a normalization nuance about apex base_url redirect behavior, which is valuable for correct usage.

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, each earning its place: the first defines the function and primary outputs; the second gives usage guidance with the sibling tool. No fluff, front-loaded with purpose, and efficient in communication.

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?

This tool is relatively simple (one optional param, output schema exists) and the description covers the key elements: temporary nature, public URL, expiration, request count, and the pairing with the requests inspector. However, it does not specify allowed HTTP methods or payload size limits, which could be relevant for a webhook endpoint but are minor gaps.

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?

Though schema coverage is 100% and the parameter (base_url) is well-documented in the schema, the description adds operational meaning: it clarifies default behavior, webhook lifecycle, and the returned fields. However, the description doesn't add much beyond the schema for the single parameter itself, as the schema already includes the normalization note.

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 purpose: creating a temporary webhook endpoint that captures incoming HTTP requests for one hour. It specifies the resource (webhook endpoint), the action (create), the constraint (temporary, one hour), and the primary capability (capturing HTTP requests). This clearly distinguishes it from sibling tools like webhook_endpoint_requests, which is for inspecting captured payloads.

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 tells when to use this tool: 'Use together with webhook_endpoint_requests to inspect captured payloads.' This provides clear guidance on the complementary relationship with a sibling tool, effectively communicating the typical workflow sequence.

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