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

Annotations already provide readOnlyHint=true and idempotentHint=true, so the description does not repeat safety. It adds behavioral value by explaining that each result row includes source_type and either external_url or media_url (never both), and that keyword does substring matching across multiple fields. This goes beyond the annotations to clarify output shape and search behavior.

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 a single, dense paragraph of about five sentences. It is front-loaded with the core action and immediately provides the geographic and material scope. Every sentence adds specific, non-redundant information. No fluff 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?

Given the tool has 9 parameters and no output schema, the description covers the main search behavior, field matching, and the key output distinction (external_url vs media_url). It does not explain pagination behavior beyond schema defaults, nor does it list all response fields (though it implies them via the matched fields). For a search tool, this is reasonably complete but could mention sorting or offset behavior.

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?

With 89% schema coverage, the schema already documents parameters well. The tool description adds context for keyword (explaining which fields it matches), source_type (defining 'youtube' vs 'deposited'), and country (specifying exactly which countries are present and excluding Niger and Ivory Coast). These clarifications are valuable beyond the schema's concise descriptions.

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 clearly states 'Search audiovisual materials by keyword and metadata' and enumerates the specific content: francophone web video from three countries plus deposited Nigerian recordings. It explains what fields are matched, which distinguishes it from sibling tools like list_audiovisual (which likely just lists) and get_audiovisual (which retrieves a single item). The verb+resource is specific and unambiguous.

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 implies usage context by naming the content scope and search fields, but it does not explicitly state when to use this tool versus alternatives like search (general), search_documents, or list_audiovisual. No 'when not to use' or comparative guidance is provided. The purpose is clear but the tool lacks explicit decision support.

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