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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so safety and idempotency are covered. The description adds real value by disclosing that returned templates include fields, media rules and example values — content the annotations cannot convey — but it says nothing about result volume, pagination, or whether the list is exhaustive.

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 tight sentences, front-loaded with the resource description and ending with the cross-tool usage note. Nothing is redundant, though the sentence is densely packed and would benefit from slightly clearer framing of the two filter parameters.

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 two-parameter, read-only listing tool with an output schema and full annotation coverage, the description supplies what is needed: what the results contain and how they feed build_video_link. The remaining gap — how filtering behaves and how large the result set is — is minor.

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 50%: 'query' is documented with examples in the schema while the 'category' enum carries no description. The description partially compensates by listing domains (festival, birthday, wedding, real estate, events) that map onto several enum values, but it does not explain how query and category combine or whether category is a hard filter.

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 resource (fill-in-the-blanks video templates) and enumerates the domains it covers (festival greetings, shop offers, birthdays, weddings, etc.), plus what each template carries (fields, media rules, example values). It stops short of an explicit verb like 'list' or 'search', and never contrasts itself with the sibling list_video_styles, so the template-vs-style distinction is left to inference.

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 phrase 'Use with build_video_link {template, fields}' usefully tells the agent this is a discovery step feeding a link-builder, which is genuine workflow guidance. However, it provides no guidance on when to use this versus list_video_styles, no guidance on query vs category filtering strategy, and no exclusions.

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