bus_history

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

With no annotations provided, the description carries the behavioral disclosure burden and does well: it declares the operation read-only, notes that already-consumed messages are included, and exposes the limit cap. It adds meaningful behavioral context beyond the schema, though it could mention ordering or return shape.

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?

The description is a single efficient sentence with front-loaded scoping ('read-only signal/message stream replay') and compact constraint notes at the end. Every phrase contributes either purpose, filtering semantics, or usage limits—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?

For a simple read-only listing tool with only four scalar parameters and no output schema, the description covers purpose, filter dimensions, included message state, and limit constraints. It is sufficiently complete for an agent to select and invoke the tool correctly.

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 0%, so the description must compensate. It explains that agent/topic/kind act as filters, that limit controls the count of recent messages, and that agent is required by default. This adds real semantic meaning to otherwise bare schema fields.

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 identifies the tool as a message-bus history reader that lists recent N messages for an agent/topic/kind, explicitly framing it as read-only replay and audit. This distinguishes it from sibling tools like bus_send and inbox_read by emphasizing historical viewing rather than sending or consuming.

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 states concrete use cases (panel display, subscriber audit, history replay) and gives a key constraint: agent is required by default, limit must be ≤200. It does not explicitly name alternative tools or say when not to use it, but the read-only framing and parameter constraints provide sufficient guidance.

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