Explain an event

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

Annotations already declare read-only/idempotent, yet the description adds real operational context beyond them: served from daemon memory, one module read when the event names a RAPID line (latency), feed lookup refused when numbering restarted (failure mode), and an explicit prompt-injection caution that controller text is data, not instructions. It also restates the safety boundary in concrete terms rather than repeating annotation booleans.

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?

Front-loads what the tool returns, then identification, then behaviour and caveats; nearly every clause carries information. It is dense and somewhat run-on, with the what-is-returned and how-to-address sections interleaved, but there is no filler.

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?

Output schema exists, so return shape needn't be explained, yet the description still summarizes the split between controller text and tool interpretation, covers staleness/replay reporting, latency sources, and an error condition. For a read-only diagnostic tool with full schema coverage, nothing an agent needs 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 coverage is 100% so the baseline is 3, but the description adds the pairing rule as a decision: seq must travel with feed, or code alone selects the newest match, and it names the source tool for seq/feed. It does not cover aroundS or controller, leaving those entirely to the schema.

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 ('one event of the controller's log, laid out for explaining it') and enumerates the exact contents returned: ABB's description/causes/consequences/actions kept separate from the tool's own annotation (category, severity, time, RAPID line) plus neighbouring events. That scoping distinguishes it clearly from get_event_log (listing) and summarize_controller.

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?

Gives concrete invocation paths: identify by seq+feed (both from get_event_log or summarize_controller), or by code meaning 'the newest event with that code'. It also sets an explicit exclusion ('It does not say what caused the event: the data does not show that'), which prevents a false expectation. It stops short of saying when to prefer this over get_event_log or summarize_controller.

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