List user functions

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

Annotations cover safety (readOnly, idempotent, non-destructive), so the bar is lower. The description adds genuinely useful non-obvious behavior: SQL Server silently omits functions the login lacks permission on without error, and it points to get_database_overview/check_permissions for diagnosing that. Doesn't mention return format, but that's acceptable.

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 tight sentences, front-loaded with the core purpose, then routing, then the non-obvious permission caveat. Every sentence earns its place.

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 2-param read-only list tool whose safety profile is covered by annotations, the description covers purpose, scope, routing, and the silent-permission-omission edge case that would otherwise cause confusing empty results. Nothing an agent needs 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?

Schema description coverage is 100%, so the schema fully documents both parameters (schema filter with example, database name). The description adds no parameter-level syntax beyond what the schema provides – baseline 3 is appropriate.

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 ('Lists the user-defined functions'), and precisely enumerates scope (scalar, inline TVF, multi-statement TVF), distinguishing it from siblings like list_procedures and get_function_definition.

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?

Explicitly says 'Use it to find functions; for one function's text use get_function_definition' – names both the use case and the alternative tool with the condition that selects it.

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