list_databases

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

Annotations already establish readOnlyHint=true, so the safety profile is covered by structured data. The description does add one genuinely behavioral fact beyond that: results are limited to what the connected user can see or connect to, so the agent knows an empty list may reflect privileges rather than absence.

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 short clause, front-loaded with the verb and resource. The '(FR-002a)' requirement traceability tag is internal noise that costs an agent a moment of parsing but is minor.

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 and no parameters, so the description is the only place an agent could learn the shape of the result — whether it gets database names, identifiers, or connection details to feed into later calls like list_tables or run_query. That gap leaves the tool slightly under-specified for a discovery entry point.

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 tool takes zero parameters, which is the baseline-4 case. Nothing in the description contradicts or complicates that, and there are no parameter semantics to explain.

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?

Clear verb+resource pair ('Discover databases') with a scope qualifier ('visible/connectable to the connected user') that tells the agent results are permission-scoped. It doesn't explicitly contrast with sibling list_tables, but the resource noun is distinct enough that an agent won't confuse the two.

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?

No explicit when-to-use or when-not-to-use guidance, and no mention of the sibling discovery tools (list_tables, describe_table) that would naturally follow this call. Usage is only implied by the zero-parameter, permission-scoped nature of the tool.

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