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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so safety is covered; the description adds the genuinely new disclosure of a $0.05 USDC x402 cost and the shape of the result (three posts with text and date). It does not mention rate limits, payment failure behavior, or handling of nonexistent/protected handles.

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?

Three short sentences, front-loaded with what is returned, followed by use cases and the cost caveat. Every sentence contributes and nothing is padded.

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 one-parameter tool with no output schema, the description covers return contents, intended use, and pricing, which is nearly everything an agent needs. Minor gaps remain around edge cases (handle not found, protected accounts) and payment mechanics.

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 coverage is 100% for the single required handle parameter, including the '@-prefix optional' note, so the schema carries the semantics. The description adds nothing about format or normalization beyond saying posts come 'from a handle'. 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 concrete verb and resource: returns the three most recent posts from a handle, with full text and date. The scope (exactly three posts) is precise. It stops short of distinguishing itself from nearby siblings like interzoid_x_profile, interzoid_x_handle, or interzoid_recent_news, leaving the agent to infer which X/News endpoint to pick.

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?

Lists scenarios (social monitoring, brand tracking, news alerts, AI agents needing current posts), which gives implied usage context. It never says when to prefer this over interzoid_x_profile or interzoid_recent_news, and gives no exclusions or prerequisites beyond the handle.

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