iam_identity_provider__list_roles

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is fully covered without the description. The description adds the useful default behavior (empty filters return everything available to the caller) and notes that subjects include non-user principals like devices. It says nothing about permission requirements, result volume, or ordering defaults.

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 text is truncated mid-sentence, which is a substantive defect rather than a stylistic one, and it carries blockquote markup, bracketed placeholders like [role]s, and an external Azure link that do not help an agent decide or call. The opening line is front-loaded, but overall it is noisy and incomplete.

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 a fully documented schema and complete annotations, the description does not need to carry much. Still, the truncated final sentence leaves the default-result-scope statement unfinished, and it omits any indication of who may see which role assignments — a relevant gap for an IAM listing endpoint.

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 100%, so every one of the seven parameters is already documented in detail, including enums, pagination, projections and ordering. The description only gestures at the subject and scope filters and adds no syntax or format detail beyond the schema. Baseline 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?

The description states a verb and resource ("List [role]s of [subject]s") and gives the underlying endpoint (GET /v2/role-assignments), which is directionally clear. However, it wavers between "roles" and "role assignments", and the final clause is cut off ("all the roles availa"), leaving the scope statement unfinished. No sibling such as iam_permissions__list_permissions is referenced to disambiguate.

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?

It gives one genuinely useful usage fact: filtering by subject or scope, and that empty filters return the unfiltered set. That is implied guidance about the default path, but there is no explicit when-to-use/when-not-to-use and no comparison to adjacent IAM listing tools.

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