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

With no annotations, the description carries the burden and does disclose real behavioral traits: full-table scan semantics, the fact that results are user-generated Instagram content to treat as untrusted input, and the filter/sort surface. It omits auth requirements, pagination, and result-set shape, keeping it short of a 5.

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?

Three sentences, front-loaded with the core action and scope, then the alternative, then the safety note. The middle sentence is dense with parenthetical filter lists, but every clause carries information and nothing is padding.

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 14-parameter, no-output-schema, no-annotation tool, the description covers scope, the sibling alternative, and the untrusted-output caveat. It stops short of explaining return fields or pagination behavior, but the parameter surface is well covered by the schema.

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 93%, so the schema already documents nearly every parameter (including enum values, defaults, and the index caveat on sort_by). The description only adds that the filter dimensions mirror search_users_by_demographics plus sort controls, which is a routing hint rather than new per-parameter meaning.

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 and resource ('Get top users') and immediately scopes it: it runs against the full user table rather than only face-detected rows. It also explicitly positions itself against the sibling search_users_by_demographics, so an agent can separate the two without opening either schema.

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?

Gives an explicit selection rule: use this when face-detection filters (gender/age/race/emotion) are NOT needed, and it names the counterpart tool whose filter set it shares. This is a clear when-to-use / when-to-pick-the-other signal rather than an implied one.

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