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

The description discloses several specific behavioral traits: same URLs, badge removed, 2400px PNG and SVG unlocked, custom branding applies, and idempotence. The title adds the credit cost, and there is no contradiction with the minimal annotations.

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 description is compact and front-loaded with the most important guarantee ('Same URLs, instantly rebranded'), then efficiently lists the unlocked benefits and idempotence. No wasted words.

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 mutation tool with no output schema, the description covers purpose, effects, cost, and idempotence, which is nearly complete. The only minor gaps are the return shape and behavior when the chart is not trial-hosted.

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?

The single parameter `id` is fully documented in the schema with its 'ast_...' format, so the schema covers the meaning. The description does not add extra parameter-level detail, matching the baseline for 100% schema description 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 names a specific verb ('upgrade') and resource ('trial-hosted chart') and lists concrete outcomes such as badge removal and unlocking 2400px PNG/SVG. It does not explicitly distinguish from sibling tools like update_asset or publish_asset, 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?

The title and description clearly imply the use case: upgrading a trial-hosted chart to premium, with a credit cost and idempotence for already-premium charts. No explicit alternatives or when-not-to-use conditions are given, but the context is clear enough for an agent.

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