read_events

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

Annotations declare readOnlyHint=false and idempotentHint=false, and the description explains exactly why: returned events are removed from the buffer, making the call non-idempotent. It further discloses overflow behavior and points at the `completeness` field in the structured result, adding real behavioral context beyond the 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?

Three sentences, each carrying distinct information: source and ordering, drain semantics, and overflow reporting. Front-loaded with the core action and no redundant restatement of the tool name.

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 two-optional-parameter read tool with an output schema, the description covers the essential non-obvious behavior: buffer draining, ordering, and where overflow/drop counts appear. Nothing an agent needs in order to call it correctly is missing.

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%, so `limit` and `node_id` are already documented in the schema. The description adds no additional meaning about parameter behavior or interactions, which is acceptable given the schema does the heavy lifting, but it does not exceed the baseline.

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 and resource ('Read the events buffered by subscribe_events') plus ordering semantics ('oldest first'), which cleanly separates this from history-oriented siblings like read_event_history. An agent can tell what it returns and where the data comes from without opening the schema.

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 makes the prerequisite explicit by tying the tool to subscribe_events, and clarifies the calling pattern ('a second call returns only what has arrived since'). It does not explicitly contrast with read_event_history or state when to prefer one over the other, so it is clear context without full exclusion guidance.

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