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

The description goes beyond the annotations by disclosing delivery semantics: duplicate tolerance and out-of-order delivery. This is meaningful behavioral context that the readOnlyHint, openWorldHint, idempotentHint, and destructiveHint do not convey. No contradiction with annotations.

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?

A single, well-formed sentence that front-loads the core action ('Read stable events') and then adds the critical caveat. Every word contributes meaning; there is no fluff or repetition of schema or annotation data.

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 parameterless read operation with rich annotations, the description is largely complete. The only minor gap is the absence of any return shape or format description, but since there is no output schema and the tool name and description imply events, this is acceptable.

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?

The tool has zero parameters and the schema is empty with 100% coverage, so there is no parameter documentation burden on the description. The baseline for zero-parameter tools is 4, and the description adds no unnecessary parameter-related information.

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 a specific verb and resource: 'Read stable events'. It identifies the operation and the object type, and the 'stable events' qualifier distinguishes it from more volatile event-related tools, though it does not explicitly name sibling alternatives.

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 implies usage context: it is appropriate to read stable events and the caller must tolerate duplicate and out-of-order delivery. However, it provides no explicit guidance on when to choose this tool over siblings like replay_event or get_webhook_deliveries, nor any when-not-to-use conditions.

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