page_observe

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

With no annotations present, the description carries the burden and does substantial work: it discloses that the tool executes exactly one action and then reports only a compact delta (url change, network requests, console entries). It does not cover error behavior, exact return serialization, or permissions, but the core behavioral contract is clear.

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 two sentences with no filler. The primary behavior and output are front-loaded, and the usage alternative is stated compactly in the second sentence.

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 there is no output schema, the description adequately summarizes what will be reported, but it leaves some context implicit: how sessionId selects a page, what the delta entries look like, and what the default settle time means. It is minimally sufficient but not fully complete for a tool with nested action objects and no output schema.

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 only 33%, and the description does not compensate. It names the action kinds (goto/reload/eval/wait) but does not explain the nested action object, the meaning of sessionId, or the waitMs default/semantics beyond what the schema already states.

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 states a specific verb-resource pair ('Run one page action') and defines the compact delta output. It also distinguishes itself from raw navigate/eval calls by naming the side-effects it reports, so an agent can separate it from page_goto and page_eval.

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 explicitly says to use this tool 'instead of a raw navigate/eval call' and gives the reason: seeing side-effects without extra tool calls. It does not enumerate when-not-to-use cases or map all sibling alternatives, so it stops short of a 5.

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