iam_users

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

With no annotations provided, the description carries the full burden. It discloses the read-only nature via '[READ][risk=low]' and adds valuable context that the root credential is never listed as an IAM user, explaining why an empty list is not a failure. It also mentions truncation reporting for the limit parameter. This is good transparency for a simple read tool, though it does not detail response format or pagination beyond the truncation note.

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 concise and well-structured. It front-loads the read/risk status, gives a one-line summary, then the root credential note, and finally the Args section. Every sentence serves a purpose, with no redundancy or filler.

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 list tool with 2 parameters and no output schema, the description covers the core aspects: purpose, edge case (root user), and parameter semantics. It lists the returned fields (status, attached policies, group membership) but does not elaborate on their structure. Given the lack of an output schema, this is adequate, though slightly more detail on the response envelope could be helpful.

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 0%, so the description must compensate. It does so effectively by explaining both parameters: limit as a maximum with truncation reporting, and target as a MinIO target name that can be omitted for default. These explanations add meaning beyond the bare type/default information in the schema.

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 indicates this is a read operation for IAM users, listing status, attached policies, and group membership. The resource is specific, but the verb is implied via the [READ] tag rather than stated explicitly (e.g., 'List'). It distinguishes from sibling tools like iam_groups and iam_policies by focusing on users with their associated attributes.

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 does not explicitly state when to use this tool versus alternatives such as iam_groups or iam_policies. It provides no exclusions or comparative guidance. The note about root credentials is an interpretive edge case, not usage direction. Only parameter-level instructions (e.g., omitting target for default) are given.

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