Get Reseller User

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

Goes well beyond the readOnly/idempotent/non-destructive annotations by disclosing the required authentication context (reseller-level, non-impersonated session), the meaning of a 404 (user does not exist), and the null-vs-numeric semantics of the quota field. These are the details an agent needs to interpret failures and results correctly.

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 short sentences, front-loaded with what is returned, then the auth constraint, then the error meaning. No filler, and each sentence carries distinct information.

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 single-record read with an output schema, the definition covers return contents, auth context, and the 404 case, so it is largely sufficient. The remaining gap is that, in a family of reseller-user tools, it does not position itself against the list/update/delete siblings or clarify how the username is scoped to the authenticated reseller.

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% and the schema already documents the username format (length, lowercase/digit/underscore pattern), so the description need not repeat it. However, the description's phrase 'plain reseller username' sits alongside 'one reseller user's details', leaving slight ambiguity about whether the parameter identifies the reseller or the target user; the description could have resolved this.

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 ('Returns one reseller user's details') and enumerates the returned fields (username, email, domain, package, suspended flag, quota), which also distinguishes it from list_reseller_users by scope (single record vs. listing).

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 prerequisite and a when-not: it must be called while authenticated as the reseller, not while impersonating a user. It does not name the alternative (e.g. list_reseller_users for enumeration, update_reseller_user for modification), so sibling routing is only implied.

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