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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuine value beyond that with the 'newest first' ordering guarantee and a concrete characterization of the corpus (francophone web video vs. deposited Nigerian recordings), which an agent cannot infer from annotations or schema.

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 sentences with the ordering and filter affordances front-loaded; no filler. The parenthetical corpus sketch is dense but earns its place by telling the agent what content is actually reachable.

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?

With no output schema and zero required parameters, the description supplies the essentials: what is listed, in what order, and which dimensions can be filtered. Pagination behavior (default 20, max 50) lives in the schema, so its absence from the description is not a real 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 80%, so the schema already documents limit, offset, country, publisher and source_type thoroughly, including the country enumeration and source_type values. The description names three of the five filters but adds no syntax, matching behavior, or format detail beyond what the schema states, so the baseline 3 applies.

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 gives a specific verb and resource ('List audiovisual materials') plus an ordering guarantee ('newest first') and the corpus scope it covers. It implicitly separates itself from get_audiovisual (single item) and search_audiovisual (keyword search) by presenting itself as a filtered enumeration, though it never names those siblings explicitly.

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?

Usage is only implied: 'Filter by country, publishing channel or source_type' suggests this is the browse-and-narrow tool, but there is no explicit statement of when to prefer it over search_audiovisual or explore_corpus. No exclusions or prerequisites are given.

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