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

Annotations already declare readOnlyHint and openWorldHint, but the description adds genuinely useful behavior: data is returned only 'when Snapchat exposes them publicly', and lookups cost credits with possible re-purchase on repeat requests. However, the cost information is self-contradictory ('at least 10 Nexscope credits' versus '1 credit per request'), which undercuts part of that value.

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 useful first sentence is followed by pasted marketing boilerplate ('View Pricing Get Snapchat Spotlight video data by URL 1 credit per request', 'Actual supplier units are reported per request', 'Examples are not guaranteed prices') that is noisy and internally inconsistent. The result is not front-loaded cleanly and several sentences do not earn their place.

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 one-parameter read-only lookup, the description covers the returned fields and the public-availability caveat, which is most of what an agent needs. It lacks any mention of failure behavior for private or deleted content and does not resolve the pricing ambiguity, leaving gaps for a tool that has no output schema.

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?

There is a single required parameter with 100% schema description coverage, so the schema already explains what 'url' means. The description adds nothing about accepted URL formats or variants, and the repeated 'by URL' phrasing carries no new meaning.

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 first sentence states a specific verb and resource: fetch public data for a Snapchat Spotlight video by URL, which separates it from social_snapchat_profile and social_snapchat_spotlight_comments. It stops short of naming those siblings explicitly, so the distinction relies on the reader inferring it from the URL-based scope.

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?

There is no statement of when to use this tool versus the sibling Spotlight comments or profile tools, and no prerequisite guidance such as needing a public URL. Usage is only implied by the phrase 'by URL'.

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