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

Annotations already declare readOnlyHint=true, openWorldHint=true and destructiveHint=false, so the description's added value is cost and caching behavior: credit charges, a live-scrape fallback, and the warning that "repeated requests may purchase data again." That is genuinely useful context beyond the annotations. It loses a point because the cost figures conflict internally ("at least 10 Nexscope credits" versus "1 credit per request"), leaving the agent unsure what a call actually costs.

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 text is bloated with scraped page artifacts ("View Pricing", "Twitter Profile API", a markdown docs link) and repeats the caching explanation already in the schema. The pricing statements contradict each other, and the return-field list is dumped without structure, so key facts are not front-loaded.

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?

There is no output schema, and the description partly compensates by enumerating expected response fields (followers_count, is_blue_verified, tipjar_settings, etc.). However, the ambiguous and self-contradictory cost model, plus the absence of any error/not-found behavior, leaves real gaps for an agent deciding whether to call it.

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 both parameters are already documented in the schema, and the description adds nothing about the handle format (with or without '@', URL accepted or not). The caching paragraph is copied verbatim from the cache_max_age schema description, so it is duplication rather than added 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 with its lookup key: "Retrieves a Twitter user's profile by handle." It also enumerates the returned fields, which confirms scope. It never names the neighboring tools (social_twitter_user_tweets, social_twitter_search_posts, social_twitter_tweet) to say how this differs from them, so it stops 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?

Usage is only implied: an agent can infer this is the tool for "given a handle, get that account's stats." There is no explicit when-to-use versus when-not guidance, no mention of alternatives such as social_find_social_profiles for handle discovery, and no note about what to do when the handle does not exist.

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