list_databases

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

The readOnlyHint annotation already establishes the safety profile, and the '[READ]' tag merely restates it. The description does add useful behavioral detail beyond the annotation — the sort order ('largest first') and the fact that sizes are broken into data vs index — but says nothing about limits, pagination, or cost.

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?

Front-loaded with the core purpose in the first clause, and the Args block is brief. The '[READ]' tag and 'Args:' header are slightly redundant given the annotation and schema, but there is no real padding.

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?

With no output schema, the description steps in to describe the return shape (table count plus data/index size) and ordering, which is what an agent needs to consume results. It is complete for a simple read-only list tool, missing only pagination/limit behavior.

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 coverage is 0%, so the description must carry the parameter burden, and it does: 'target: Target name from config; omit for the default' explains both the meaning and the omission behavior for the single optional param.

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 ('User schemas') plus the returned fields (table count, data/index size) and ordering (largest first). It is clearly distinguishable from size-oriented siblings like table_sizes or list_engines, though it never names an alternative.

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?

Usage is only implied: an agent can infer this enumerates databases, but there is no statement of when to prefer it over table_sizes, overview, or list_engines, and no exclusions or prerequisites.

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