list_users

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

readOnlyHint=true is consistent with the '[READ]' tag, and the description goes well beyond it: it discloses that truncation is measured via one extra fetched user, that missing IdP fields come back as null rather than empty string, and that the default page bound is 200. With no output schema, this is exactly the behavioral load the description should 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?

Front-loaded with the one-line purpose, then an Args block, then the return contract. Every sentence earns its place — the truncation and null-handling notes are non-obvious and actionable, not 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?

With no output schema, the description supplies the return shape (users/returned/limit/truncated) and the semantics of truncated and null fields. For a 3-parameter, no-required-arg listing tool, nothing an agent needs to call it correctly 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 description coverage is 0%, so the description must compensate, and it documents all three parameters: search (optional username/email), max_results (page bound, default 200), and target (IdP target name from config, omit for default). This adds meaning the bare schema titles do not.

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 (list) and resource (users) with an explicit scope constraint ('in the realm') and normalization note across Keycloak/authentik. This clearly separates it from user_count, user_detail, and list_groups without opening any 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 operational context: search is an optional username/email filter, target defaults when omitted, and it explicitly instructs re-running with a higher max_results before drawing a realm-wide conclusion when truncated is true. It does not name alternatives (e.g., when to prefer user_detail), so it stops 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.