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

The annotations already establish readOnlyHint=true, openWorldHint=true, and destructiveHint=false. Beyond that, the description adds useful behavioral context: it lists the returned profile fields, story metadata, spotlight engagement stats, and notes that completed lookups cost credits and repeated requests may purchase data again. The appended pricing snippet ('1 credit per request') conflicts with the earlier 'at least 10 Nexscope credits' statement, which muddies the cost disclosure.

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 opening two sentences are front-loaded and useful, covering purpose and return shape. However, the trailing pricing block is noisy, repetitive, and internally inconsistent ('at least 10 Nexscope credits' vs. '1 credit per request'), and it reads like pasted pricing-page text rather than a coherent part of the tool definition.

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 single-parameter profile lookup with no output schema, the description is fairly complete: it explains the input, the returned profile and story structures, and the credit-cost behavior. The main gap is the contradictory pricing detail, which could leave an agent unsure about the actual cost.

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 one required parameter, and schema description coverage is 100%, so the schema already fully documents 'handle' as the Snapchat username. The description only repeats that the lookup is 'by handle' and adds no format, validation, or handling detail beyond the schema.

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 states a specific verb and resource: 'Retrieves a Snapchat user's public profile by handle.' It also lists the main returned sections (userProfile, highlightStoryMetadata, spotlightStoryMetadata). It does not explicitly contrast itself with the sibling social_snapchat_spotlight, but the 'user profile by handle' scope is clear enough to distinguish the core operation.

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: an agent can infer it should call this when it has a Snapchat handle and needs profile data. There is no explicit when-to-use guidance, no when-not-to-use guidance, and no named alternative such as social_snapchat_spotlight for spotlight-only retrieval.

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