Get User

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

readOnlyHint=true already declares the safety profile, so the description only adds that matching is exact and lists the attribute types accepted. It says nothing about behavior when no user matches (null vs error) or how the domain parameter affects resolution.

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?

A single front-loaded sentence with the identifier formats immediately after the purpose. Every clause earns its place and nothing is padded.

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?

An output schema exists, so return values need not be explained, and readOnlyHint covers safety. The remaining deficit is the undocumented 'domain' parameter and the absence of any not-found behavior, which matters for an exact-match lookup tool.

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 carries real weight and does add value for 'identifier' by naming sAMAccountName, UPN, mail and cn as accepted forms. The 'domain' parameter is left entirely undocumented in both schema and description, leaving a meaningful gap.

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 uses a specific verb and resource ('Get a single AD user') and enumerates the accepted identifier types, which distinguishes it from the bulk sibling find_users. It does not explicitly name the sibling it differs from, but 'single' plus 'exact match' makes the scope unambiguous.

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?

'exact match' implies this is for precise lookups rather than pattern searches, which implicitly routes the agent away from find_users. However, it never states when to prefer this over find_users or get_by_dn, nor any prerequisites for the identifier formats.

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