Search

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

Annotations already cover read-only and idempotency, but the description adds real behavioral context: externalId lookups match ids Plex stores on every movie/show library and usually return one item or none, and the call reads every movie and show library in full so it costs a second or two on a large server. It does not address what happens when query and externalId are both supplied or both omitted.

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?

Purpose and grouping are front-loaded, then routing guidance, then the externalId mode. The externalId sentence is long and comma-heavy, but every clause carries information an agent needs; no filler sentences.

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 read-only search tool with no output schema, the definition supplies scope, result shape, sibling routing, and the alternate id-lookup mode with its performance characteristic. Only the interaction between optional parameters and limit behavior is unstated, a minor gap.

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 only 33%, and the description compensates well for externalId, explaining its format, matching basis and typical cardinality beyond the schema's one-line hint. However, 'query' matching semantics (exact, prefix, fuzzy) and 'limit' (default 20, capped at 50) are left entirely to 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 definition states a specific verb and resource ('Global search across ALL libraries') and enumerates the media types searched, then adds what the output looks like ('hits grouped by type'). It also distinguishes itself from list_media/filtering siblings by making the cross-library scope explicit.

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?

Explicit routing is given for each result type: person hits go to person_credits, item hits go to get_item. It also carves out a distinct mode (externalId instead of query) and states precisely when that mode applies — when you already hold an IMDb/TMDB/TVDB id.

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