list_indexers

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

With no annotations present, the description carries the full burden of disclosure. It goes beyond a generic listing claim by stating that secret field values are masked by Sonarr and that the fields array is omitted. This is valuable behavioral context an agent would not otherwise know.

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 tightly written sentences with no filler. The action is front-loaded, and the second sentence provides both a behavioral caveat and a routing hint.

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-parameter listing tool with no output schema and no annotations, the description adequately conveys what is returned, what is omitted, and where to get the omitted data. A richer return-type breakdown would be nice, but it is not necessary to select and invoke the tool correctly.

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 and the input schema is empty, so the 0-parameter baseline of 4 applies. There is no parameter information to add because none 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 opens with a specific verb and resource: 'List the configured indexers.' It also distinguishes itself from get_indexer by noting the omitted fields array, so an agent can tell them apart immediately.

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 description explicitly tells agents to use get_indexer when they need the fields array, giving a clear alternative for a specific need. It does not broadly enumerate when not to use list_indexers, but the targeted guidance is sufficient for this simple listing tool.

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