security_who

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

The readOnlyHint annotation already tells the agent this is a safe, non-mutating call, so the description would need to add something beyond that to earn credit. It adds nothing about what is returned (users, roles, groups?), whether results are paginated or capped, or the cost of the lookup.

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?

It is a single short sentence, so it is certainly not bloated, but half of it is spent on the UI location 'Roles & groups tab' rather than on behavior an agent can act on. Briefness here reflects omission rather than disciplined editing.

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 two-parameter tool with no output schema, no schema descriptions, and only a single readOnly annotation, the description should carry the burden of scope and parameter meaning. Instead it supplies a UI reference and a restatement of the name, leaving the agent unable to predict arguments or results.

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% across both parameters, so the description must compensate and does not: neither 'database' (required) nor the optional 'table' is named or explained. At best 'reverse lookup' faintly implies the arguments identify the protected object, but the difference between supplying a database alone versus a database plus table is left entirely undocumented.

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 phrase 'Reverse lookup ("who can access")' conveys the general idea of resolving access from an object back to principals, but it never states what resource is being resolved (table? database? role?) nor what the output represents. It also fails to distinguish itself from the near-identical sibling who_can_access, which appears to promise the same thing.

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?

There is no when-to-use guidance, no prerequisites, and no mention of alternatives. The most obvious alternative, the sibling tool who_can_access, is never referenced or differentiated, leaving the agent to guess which of the two to call.

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