list_databases

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

No annotations are supplied, so the description carries the full disclosure burden. It partly discharges this by describing what the response contains and that policy fields may be absent ("when one is set"), but it never states read-only/safety characteristics, whether the list can be empty, or how it relates to permissions/connections. Adequate but not rich for an unannotated tool.

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?

Two sentences, both front-loaded: the first defines the payload, the second defines when to call it. The parenthetical of policy fields is compressed but readable, and nothing is redundant with structured fields since there are none for parameters.

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 zero-param, zero-annotation tool with no output schema, the description must explain the return shape itself, and it does so by naming the fields returned and the conditions under which policy appears. There is no meaningful gap an agent would need filled before calling 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?

The tool takes zero parameters, so there is no parameter semantics for the description to add; the baseline for a parameterless schema applies. The description does not waste effort restating schema details that do not exist.

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 pairs a specific verb and resource ("List all configured database connections") with an enumeration of what each entry contains (id, type, label, description, policy details). Combined with the sequencing instruction "Call this first," an agent can distinguish it from run_query, describe_table, and list_tables without opening any schema.

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?

"Call this first to discover which database_id to use" gives explicit when-to-use guidance and names the outcome (obtaining a database_id) that motivates the call. It stops short of a 5 because no alternative or negative case is stated, though for a zero-param discovery tool the entry-point instruction covers the realistic decision.

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