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

With no annotations, the description carries the full burden; it does disclose that structure mode omits the page body and returns meta plus outline plus statistics, which is genuinely useful behavioral context. It says nothing about failure behavior, truncation (the length default of 0 is unexplained), or whether fetched pages are cached, so the disclosure is partial.

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 action before the mode breakdown and the batch-use tip. The final sentence partially repeats the schema's format description, but it earns its place by tying structure mode to a concrete workflow.

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 7-parameter tool with a full output schema, the description covers the one decision an agent must make (which format) and gives a practical selection rule. The remaining parameters are schema-documented, so the omission is acceptable, though a note on what length=0 means would round it out.

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 100%, so the baseline is 3. The description restates the schema's own format semantics and elaborates the structure option for batch use, but adds nothing about length, delete_links, delete_images, or the heading limits, so it does not exceed the schema's information.

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?

Names a specific verb and resource (fetch page content by URL) and explains the two modes of retrieval, so the agent knows exactly what it gets. It does not, however, differentiate itself from neighboring tools such as get_page_screenshot or get_pages_summary, leaving that inference to the agent.

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 an explicit usage rule: for a batch review of N pages from the top of the SERP, use format=structure to save context. That is concrete guidance tied to a scenario. It stops short of saying when to prefer md over html, or when to use this tool instead of the summary/screenshot siblings.

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