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

Annotations already declare readOnlyHint, openWorldHint, and destructiveHint, so the safety profile is covered. The description adds useful behavioral context: it searches a public database, includes reference films that cannot currently be streamed, and excludes private records and availability outside GuideDoc. This is meaningful context beyond what the annotations alone provide.

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?

The description is compact and front-loaded: the first sentence states the main purpose, the second clarifies scope, and the third gives the important exclusions. The Args block is minimal and directly supplements the under-documented schema without 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?

For a single-parameter search tool with an output schema and readOnly/openWorld annotations, the description is complete. It explains what to search, what is included, what is excluded, and what kinds of queries to pass. No essential information is missing for correct invocation.

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 carries the full burden of explaining the query parameter. It does so well by defining the query as a 'Documentary title, director, topic or keyword' and giving concrete examples like 'Senna' or 'climate change'. The agent receives everything needed to construct a valid query.

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 names a specific verb ('Search') and resource ('GuideDoc's public film database'), and specifies the supported lookup dimensions: title, director, topic, or keyword. It also distinguishes the tool by excluding fiction, private records, and outside-GuideDoc streaming, so an agent can tell exactly what scope this tool covers.

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 says when to use the tool ('Use this when someone seeks documentary films...') and provides clear when-not conditions ('Do not use for fiction, private GuideDoc records or streaming availability outside GuideDoc'). It does not name an alternative sibling such as fetch, but the conditions themselves are unambiguous enough for most routing decisions.

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