Get a browser fingerprint

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

Beyond annotations (readOnlyHint, openWorldHint), the description discloses a key edge case: empty object with HTTP 200 when no match. It also explains the behavioral requirement of internal consistency and the anti-fraud consequence of editing, adding valuable non-obvious context.

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 with no redundancy. The first states the core action, the second provides usage and edge-case info. Every sentence is informative and front-loaded.

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?

Despite lacking an output schema, the description effectively covers the tool's main purpose, the critical usage instruction (verbatim pass-through), and the failure mode. The read-only nature is already in annotations, and the edge case is explicitly noted, making the description complete for an agent.

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 67%, with screen and browser_version already described. The description adds that the params act as filters, clarifying the role of the optional inputs. While it doesn't detail each param, it provides enough context to understand the filtering behavior, adding modest value 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 samples a real-world fingerprint from the Dolphin dataset, using a specific verb and resource. It also differentiates from siblings like get_useragent and list_webgl by explicitly tying the output to create_profile, making its purpose distinct.

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?

It gives explicit when-to-use guidance: pass the returned object verbatim as create_profile's fingerprint. It also warns against editing values piecemeal, which instructs on proper usage and what to avoid. This directly tells the agent how to use the tool correctly.

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