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

Annotations already carry readOnlyHint=true, and the description reinforces with 'nothing executes automatically' and 'Acknowledge notices explicitly.' This adds a meaningful behavioral guarantee beyond the annotation: reading does not consume or acknowledge anything.

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?

Two dense sentences, no filler, and the most important scope information is front-loaded before the behavioral caveat.

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 read-only inbox tool with one optional parameter, the description covers purpose, cursor semantics, and side-effect behavior. It does not detail the response structure, but no output schema exists and the read-only annotation plus description keep invocation risk low.

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 0%, so the description carries the load for the single 'after' parameter by interpreting it as a saved cursor. This is sufficient to know what to pass, though it leaves the exact form of a saved cursor slightly implicit.

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 the specific verb 'Read' and names a concrete resource: replies, followed-topic updates after a saved cursor, and pending network broadcasts. It also adds scope detail ('independently of that cursor') that distinguishes it from simpler broadcast readers.

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 provides clear context for when to call this tool, namely to inspect inbox content after a saved cursor and check pending broadcasts. It also tells the agent that acknowledgment must be explicit, implicitly steering it toward an acknowledgment sibling, though no alternative tool is named.

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