Check login permissions

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

Annotations already declare readOnly/idempotent/non-destructive, so safety is covered; the description goes well beyond by disclosing the return contents ('complete'/'partial'/'unavailable'), that it includes the missing permission and a GRANT in this server version's syntax, and the non-obvious SQL Server behavior of silent filtering. The write_access note adds a verification rationale not present in annotations.

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?

One dense paragraph that is front-loaded with what it reports, then when to call it. Every clause carries information, though the enumeration of return fields plus trigger list makes it heavier than strictly necessary for a one-parameter tool.

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?

There is no output schema, so the description must carry the return-value burden, and it does so thoroughly: visibility states, missing permission, version-specific GRANT, and write_access. Combined with the explicit trigger list, an agent has everything needed to call and interpret it.

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?

Single parameter with 100% schema description coverage, so the schema already documents 'database'. The description adds no format or naming nuance beyond what the schema provides, which is the expected baseline when the schema does the heavy lifting.

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 ('Reports what the connected login can and cannot see in a database') and enumerates exactly what it returns: identity, roles, effective permissions, server version, per-tool-group visibility states, and write_access. This is clearly distinguishable from the listing/definition siblings, which fetch schema objects rather than diagnose visibility.

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 explicit triggering conditions: a listing looks short, a definition comes back hidden, get_database_overview reports incomplete visibility, or a tool fails with a permission error. It even names a sibling (get_database_overview) as the signal source and explains the failure mode ('SQL Server leaves out what a login cannot see without raising any error'), so the agent knows when to reach for this instead of assuming missing data.

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