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

Annotations already establish readOnly, idempotent, non-destructive behavior. The description adds a concrete operational fact ('1 credit') and the handle-based lookup, but does not disclose caching behavior, freshness semantics, or return characteristics, leaving room for more context.

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 short sentences with no filler; the core purpose is front-loaded and the credit cost is a useful standalone fact. Every word earns its 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 simple read-only lookup with fully documented parameters and safety annotations, the description is almost sufficient. The main missing piece is guidance on output shape or when to prefer siblings, but that is already counted under usage guidelines.

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 the schema documents both handle and fresh adequately. The description's 'by handle' and cost are consistent, but it adds no parameter-level guidance beyond the schema, matching the baseline for high coverage.

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 identifies the resource as a single X user's profile addressed by handle, which distinguishes it from sibling tools like get_users, get_user_tweets, or get_followers. It lacks an explicit verb, relying on the tool name's 'get', but the intent is unambiguous.

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?

No guidance is given about when to use this tool instead of the many sibling tools, such as get_users for multiple profiles or get_tweets for user content. The description does not state exclusions or alternative conditions.

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