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

readOnlyHint=true already tells the agent this is a safe read, so the description only needs to add context. It contributes the single-application scoping and the REST path, but says nothing about pagination behavior or result shape beyond what the schema's iterator/limit fields imply.

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 short sentences, zero waste, with the purpose and scope front-loaded before the REST reference. Every clause earns its place.

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 read-only list tool with a fully documented schema and no output schema, the definition covers what an agent needs to invoke it correctly. The only mild gap is that pagination workflow (first page vs cursor) is left entirely to the schema.

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%: app_id, limit, order, and iterator are all documented with meaning, defaults, and cursor semantics in the schema itself. The description adds no parameter detail, so baseline 3 applies.

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?

States a specific verb (List) and resource (webhook endpoints) with an explicit scope constraint ('registered for one application'), and the REST path confirms the resource. An agent can distinguish it from svix_get_endpoint (singular fetch) and svix_list_endpoint_messages (messages, not endpoints).

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?

No when-to-use or when-not-to-use guidance and no named alternatives, despite many sibling list/get tools. The 'for one application' phrasing implies the required context but nothing routes the agent between this and, say, svix_list_endpoint_messages or svix_get_endpoint.

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