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

Annotations already cover the safe read-only, idempotent nature of the operation. The description adds useful behavioral context beyond annotations by disclosing the return value (handle with confidence score) and the $0.05 USDC cost via x402.

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 concise, action-first sentences with no filler. The description efficiently covers purpose, scope, output, and cost without redundancy.

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 low-complexity tool with one fully documented parameter and safety-providing annotations, the description supplies the essential missing details: the return format and the monetary cost. Nothing necessary for correct invocation is absent.

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%, and the schema already provides a clear description and an example for the single parameter. The description adds some synonym detail but no new formatting or usage semantics, so the baseline of 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+resource ('Retrieve the X handle') and enumerates accepted entity types, clearly distinguishing it from related siblings like interzoid_x_profile and interzoid_x_last_three_posts. The scope is immediately understandable.

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?

The description conveys the core use case and implies when to use it, but provides no explicit when-not-to-use guidance or pointers to alternative tools. It leaves the agent to infer the right situation from the listed entity types.

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