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

Annotations already establish readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds genuinely non-obvious behavior beyond that: matching is against a fixed lookup list identical to the public decoder page (i.e. deterministic table matching, not free-form generation), there is no authentication, and the response will include a commercial upsell — useful disclosure for an agent deciding how to present results.

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 sentences, both front-loaded: the first states purpose and output, the second states the matching mechanism and access terms. No filler, and the most decision-relevant information (what you get, what it costs) comes first.

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 single-parameter, read-only lookup with no output schema, the description covers what the tool does, how it matches, what it returns at a high level, and that access is free. The only gap is behavior when no match is found, which an agent would want to know before reporting results.

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?

With one parameter at 100% schema coverage, the schema already explains that the value is the error message or keywords from it. The description reinforces that loose keyword matching works ('Matches the text against the same list'), but adds no format, length, or normalization guidance beyond the schema.

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 opens with a specific verb and resource ('Explain an error message from an app built on Bubble') and then enumerates what the agent gets back: likely cause, a link to the full fix, and a paid service offering. It is unambiguous and clearly distinct from the sibling audit/scan tools.

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?

Usage is implied — the agent should call it when it holds a Bubble error message — and the 'Free, no key' line removes a common prerequisite concern. However, there is no explicit when-not guidance and no named alternative for related diagnostics, so the agent must infer the trigger condition from the purpose statement alone.

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