browser_observe

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

With no annotations, the description carries the full burden. It usefully discloses that the call takes no action and that a screenshot path may be returned 'when safe', but says nothing about permissions, rate limits, session validity, or what 'safe' means. Partial behavioral coverage only.

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 the core read-only purpose. Every sentence contributes something, though the trailing screenshot clause is vague enough that it earns slightly less than a perfect score.

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?

An output schema exists, so return-value explanation is not required, and the description covers the essential read-only purpose and detail escalation. The remaining gap is the un-explained 'screenshot' boolean against thin schema coverage, which keeps it from a 5.

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 33%: 'session' is documented in the schema, 'detail' has an enum but no prose, and 'screenshot' is entirely undocumented. The description compensates for 'detail' with the compact-vs-full guidance and hints at screenshot output, but the boolean 'screenshot' parameter remains unexplained.

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 specific verb+resource ('Read the current page') and explicitly scopes it as non-mutating ('without taking action') in an 'existing session', which separates it from action-oriented siblings like browser_act and browser_navigate. It does not name those siblings, 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?

Gives a concrete conditional for the 'detail' parameter ('Use full detail when the compact snapshot omits needed content'), which tells the agent when to escalate. No explicit when-not-to-use or exclusion relative to browser_act/browser_tabs, so it is clear context without full routing.

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