ff_eval

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

No annotations are provided, so the description bears full transparency burden. It discloses that the code runs in a real tab with DOM and storage access, but does not explain scope limitations (e.g., 'not page globals'), return value handling, side effects, or execution mode (sync/async). Partial transparency but significant gaps remain.

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 exceptionally concise with two sentences that convey core purpose and operational context. No unnecessary words or 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?

Given the lack of output schema and annotations, the description is incomplete. It does not describe return values, error conditions, or how to handle results. For a tool executing arbitrary JS, these omissions hinder safe and effective use.

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 0%, and the description does not explain either parameter. While 'code' is implicitly the JavaScript to run, 'tabId' is not mentioned at all, leaving ambiguity about how to specify the target tab. The description fails to add meaning 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 clearly states the tool runs JavaScript in a real tab with access to DOM and storage, differentiating it from sibling tools like 'eval_js' which may run in a different context. The purpose is specific and 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?

The description implies usage in real browser context but does not provide explicit guidance on when to use versus alternatives or when not to use it. The mention of needing the bridge add-on is helpful but insufficient for clear usage guidelines.

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