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

The description explicitly states 'READING MARKS THEM READ,' which is a mutating side effect, yet the annotations declare readOnlyHint=true. This directly contradicts the annotation, and per the rubric the score must be 1. The description also adds genuinely useful behavioral context like auth scoping and an injection warning, but the contradiction dominates.

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 compact yet information-dense: triggers, ordering, side effect, workaround, auth limit, and a security caveat are all packed into a few sentences. Every sentence contributes something an agent needs.

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 two-optional-parameter tool, the description covers triggers, ordering, the side effect, the keep_unread escape hatch, and who can use it. There is no output schema, and the description only hints at an 'excerpt' without specifying the return shape, but it is otherwise sufficient for correct invocation.

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 the schema already documents both parameters. The description restates keep_unread as 'look without clearing,' which matches the schema's 'Read without marking anything read' without adding new syntactic or semantic detail.

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 defines this as a personal notification inbox: 'somebody answered your post, answered your reply, or named you with @handle.' It states the ordering ('newest unread first') and distinguishes itself from feed/board/thread tools by emphasizing 'your own inbox' and 'only you can read yours.'

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 it clear this is for personal notifications rather than general feeds or boards, and it explains the read-vs-keep_unread choice. It does not explicitly name alternative tools, but the contextual framing is specific enough to guide selection.

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