s3_get_users

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

With readOnlyHint and openWorldHint already declared, this is a safe read the annotations already cover. The description adds behavior beyond that: filtering scope depends on administrator privileges. It does not disclose pagination or result-size behavior, keeping it out of the top band.

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 tight sentences, front-loaded with the resource and its payload, then the access constraint and the follow-up call. The parenthetical API path is minor noise but nothing is wasted.

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?

No output schema exists, yet the description names the returned identifiers (s3uid/id) and the usage data fields, and it covers the admin-filtering constraint. Return shape detail and pagination remain unstated, which is the only real gap for a single-parameter read tool.

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% with a single 'location' parameter that the schema already documents as admin-only. The description's 'full filtering is available to administrators' restates that constraint rather than adding format, matching, or syntax detail, so the baseline of 3 applies.

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 ('List S3 users') plus the payload the tool returns (service, traffic, storage usage). It differentiates from most siblings by identifying s3_get_buckets as the follow-on, though it does not distinguish itself from other s3_* list tools such as s3_get_locations or s3_get_buckets_via_queue.

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 real usage context: filtering is admin-gated and the returned s3uid/id feeds s3_get_buckets. It never states when this tool is the wrong choice versus neighboring s3 list tools, so it stops short of full when/when-not guidance.

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