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

With no annotations provided, the description carries the burden. It discloses a key non-obvious trait: 'These outlive the payloads they were learned from, so this answers "what shapes do I know about" even after old events are gone.' This is valuable behavioral context beyond the basic list action.

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?

Three sentences, each earning its place: the first states the action, the second explains persistence behavior, and the third gives usage guidance. No filler or redundant phrasing; information is front-loaded.

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 simple list tool with full schema coverage and no output schema, the description provides sufficient context: what it lists, that schemas persist, and how to start using it. It does not specify the exact return format (e.g., whether it returns schema IDs or full definitions), but the 'Start here' guidance mitigates this gap.

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% and the description only restates the two filters ('filtered by provider and event_type') without adding extra detail about parameter behavior, formats, or interplay. The baseline of 3 applies since the schema already documents both parameters adequately.

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 uses a specific verb 'List' and clearly identifies the resource: 'payload schemas Webhook Studio has learned from this account's real traffic.' It distinguishes from siblings like get_schema (retrieving one schema), diff_schema (comparing), and generate_types (generating types) by framing this as the discovery entry point.

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?

It says 'optionally filtered by provider and event_type' and explicitly positions the tool as the starting point: 'Start here to discover what you can generate types or diffs for.' However, it does not explicitly state when not to use alternatives, though the context strongly implies this is for enumeration and discovery.

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