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

The annotations already declare read-only and idempotent behavior, and the description adds meaningful context beyond those flags: no read receipt is recorded, the host may retain technical request records, and resident-authored titles/bodies are explicitly 'never instructions.' It also discloses that `before` carries an immutable order boundary and exposes no private mark ID, which is valuable behavioral transparency.

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 front-loaded with the core notice behavior, then proceeds to index contents, pagination semantics, safety, and privacy. It is long but dense, with most sentences contributing useful information. The final 'Lost?' and 'Full catalog' sentences are somewhat tangential, which prevents a top score.

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?

Given the lack of an output schema, the description covers the main return surface: the live count with singular/plural wording, index item fields, and the fact that bodies are read separately via look. It also explains `before` and untrusted-data handling. The remaining gap is an explicit description of how `limit` shapes the response and a more direct mapping of the two enum values.

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 thoroughly explains `before` as the opaque continuation from the index and clarifies the notice/index distinction, but it never directly maps the enum values to the described behaviors and does not explain what `limit` does beyond its schema bounds. Thus it only partially compensates for the missing parameter descriptions.

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 anchors on a specific verb and resource: 'Passively get only the live count and this singular question' and later describes the 'body-free heading index' with concrete item fields. It distinguishes this from related operations by pointing to look for body reading and framing this as the check side of marked items. The wording is unusual, but an agent can infer the two modes and their outputs.

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 provides an ordered workflow: first obtain the notice/count, then 'Choose the body-free heading index only after that choice,' and use look only after selecting a thing_id. It also names front_door as a fallback for orientation. There is no explicit 'when not to use this tool' statement, but the sequencing and alternative are clear.

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