Profile

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

Adds context beyond the annotations: credit consumption, the confirm=true gate, and an explicit clarification that despite the write-like POST verb the call does not publish to social platforms — which reconciles the readOnlyHint=false flag. It does not cover failure modes or credit-refund behavior, but for this tool that is a minor gap.

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?

Front-loads the core purpose and return fields, then the operational caveats. The trailing 'Read-like POST requests do not publish to social platforms' sentence is slightly awkward and appends after the credits note, but every sentence carries information and nothing is filler.

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?

With no output schema, the description carries the return-value burden and discharges it by enumerating both the standard profile fields and the extras (verification_info, tipjar_settings, highlights_info, creator_subscriptions_count). Combined with the cost/confirm disclosure and 100% schema coverage, an agent has everything needed to call it correctly.

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 handle, account, confirm, and cache_max_age are already fully documented in the schema. The description restates confirm=true and the credit cost but adds no new syntax or format detail, so the baseline 3 applies.

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 ('Retrieves a Twitter user's profile by handle') and enumerates the returned metadata, which cleanly distinguishes it from siblings like twitter_user_tweets, twitter_tweet_details, or other platforms' *_profile tools. An agent can identify the target and output without opening the schema.

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 a concrete precondition ('requires confirm=true') and a cost signal ('potentially consumes paid API credits'), so the agent knows the call is gated and metered. It does not, however, name an alternative tool or state when NOT to use it (e.g., versus twitter_user_tweets for tweet data), so it falls short of full routing guidance.

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