nexus_get_user_by_name

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

Beyond the readOnly and idempotent annotations, the description discloses exact-match behavior, the clean failure mode, and the precise return shape including the null case. This tells an agent exactly what to expect when calling the tool.

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 well-structured and front-loaded: the core purpose appears in the first line, the distinguishing contrast follows, and the return contract is placed at the end. There is no filler or redundancy.

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-parameter read-only lookup with a rich annotation set and an output schema, this description is complete. It covers purpose, exact-match behavior, failure semantics, return value shape, and a concrete use case. Nothing needed for correct invocation 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?

The input schema already fully describes the username parameter as exact and case-sensitive with an example. The description adds the use-case context of converting username to memberId, but most parameter semantics are already covered by 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 states a specific verb and resource: getting a user profile by exact username, and explicitly distinguishes itself from the fuzzy search_users sibling. It is immediately clear what this tool does and how it differs from similar lookup tools.

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 clearly contrasts itself with nexus_search_users and gives a concrete use case: converting a username to a memberId for user mutation tools. It does not enumerate other alternatives, but the exact vs. fuzzy distinction provides enough guidance for the main alternative.

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