arr_add

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

With no annotations provided, the description carries the full burden and does well by disclosing the dry-run/confirm safety pattern and the implicit side effect of search_now starting downloads. It omits permission/auth requirements, what happens if the item already exists, and error behavior, leaving some behavioral gaps.

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 action, followed by a compact per-parameter list and the confirm workflow. Every line earns its place and there is no filler or repetition.

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 six-parameter mutation tool with no annotations, the description covers purpose, parameter meaning, and the critical confirm workflow; the presence of an output schema removes the need to describe return values. Nothing an agent needs to invoke it correctly 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?

Schema description coverage is 0%, so the description must compensate, and it does: it defines service, explains external_id's dual meaning (TVDB for shows, TMDB for movies) and where to get it, clarifies the empty-string default semantics for quality_profile and root_folder, and describes search_now and confirm. All six parameters get meaningful interpretation beyond the bare schema.

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+resource pair ('Add a show to Sonarr or a movie to Radarr') and names both target services, so the agent immediately knows the effect and scope. It is clearly distinguishable from siblings like arr_search (lookup) or arr_queue (monitoring).

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?

It gives explicit procedural guidance for the two-phase confirm flow ('First call without confirm... then call again with confirm=true') and points to arr_search as the source of the external_id. It does not state when *not* to use the tool (e.g. for existing items already in the library), so it stops just short of the top band.

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