silva_list_databases

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

With no annotations, the description carries the disclosure burden, and it does state the return contents (database IDs, full names, available taxonomies). Since this is a parameterless enumeration tool with no mutation risk, there is little additional behavior to disclose; only caching or refresh semantics are left unstated.

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, front-loaded with the action and resource, with the second sentence efficiently covering return values. No filler.

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 parameterless, annotationless, output-schema-less discovery tool, the description supplies everything needed: what it returns and why (databases plus their taxonomy systems). Nothing essential to invocation 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?

The tool takes zero parameters, so the baseline of 4 applies. There is nothing in the schema to clarify, and the description adds no misleading parameter expectations.

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 ('List all available SILVA databases') plus the secondary payload (supported taxonomy classification systems). This clearly distinguishes it from siblings like silva_search or silva_browser, which operate on database contents rather than enumerating them.

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?

The intent is implied: call this to discover database IDs and taxonomies before invoking silva_search, silva_browser, or silva_sequence_detail. However, no explicit when-to-use statement or named alternative is given, so the agent must infer the discovery role from the sibling set.

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