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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds value beyond that with result ordering, the cursor round-trip contract, and the mutual-exclusivity constraint on filters — behavior an agent could not infer from the structured fields alone.

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?

Three short sentences, zero redundancy, with the core action and ordering front-loaded before pagination and filter constraints. Every clause carries a constraint the agent needs to call the tool correctly.

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 read tool with no output schema, the description covers ordering, pagination and filter exclusivity — the main behavioral risks. It stops short of sketching what a listed video contains or noting that the response carries the next_page_token, which would have closed the loop for an agent planning a follow-up call.

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 100%, so the baseline is 3. The description earns a point above baseline by stating the cross-parameter constraint that no filter field's own description mentions: at most one of client_id, brand_id or product_id may be set.

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?

States a specific verb and resource ('List videos in the account') plus a meaningful scope qualifier ('newest first'), which lets an agent distinguish it from the singular get_video sibling without opening either schema. It does not explicitly name the sibling it is not, so it falls short of a 5.

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?

Gives concrete procedural guidance for pagination ('Pass next_page_token from a previous response to fetch the next page') and a hard selection rule ('At most one of client_id, brand_id, product_id may be set'). What it lacks is an explicit statement of when to prefer this over get_video or how filtering combines with mine_only.

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