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

Beyond the lone readOnlyHint annotation, it discloses login gating, the 7-day window, deduplication of self-views and bots, and that anonymous views expose only an ipHash-based count with no identity. The 'empty is normal, don't retry' warning is exactly the kind of behavioral context annotations cannot carry.

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?

Tight and front-loaded: login gate first, then scope, then behavioral caveats, then the combo chain. Dense but every clause carries information; slight density makes it borderline, hence 4 rather than 5.

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?

With no output schema, the description compensates by explaining the return shape (namedCount/total vs page length, anonymous ipHash counts) and what to do on empty results. Nothing essential for correct invocation 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 days and limit are fully documented in the schema. The description's note that namedCount/total is not the page length adds clarity but concerns output rather than parameter usage, so baseline 3 is appropriate.

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 (read) and a precisely scoped resource: named views on profile/product/needs within the last 7 days. An agent immediately knows this is a 'who viewed me' read, distinct from generic feed or notification tools.

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?

Provides login requirement, a no-retry rule for empty results, and a follow-up routing chain (viewerId→get_creator→start_conversation/follow_creator). It lacks an explicit 'use X instead of this tool' comparison against siblings, so it falls short of a 5.

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