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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds meaningful behavioral context beyond annotations: it explains that the page will be truncated again if still too long, and that the result is the next section of the same page. This gives agents an accurate model of the tool's iterative behavior without contradicting annotations.

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 three short sentences and is front-loaded with the core purpose. Every sentence earns its place: the first states the action, the second explains the input, and the third describes the output behavior. There is no filler or redundant detail.

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 simple tool with two parameters and an output schema, the description covers the main action, input semantics, and behavioral nuance (re-truncation). The only gap is the undocumented 'maxChars' parameter, but given its optional nature with a default, the overall description is sufficient for an agent to correctly invoke the tool.

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%, so the description must compensate. It does explain the 'token' parameter as coming from a truncation marker, which is valuable. However, it does not describe 'maxChars' at all, leaving its purpose and effect undocumented. With two parameters, one is explained and one is neglected, so the description partially compensates but is not complete.

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 clear verb ('Read') and a specific resource ('remainder of a page that was truncated'), and clarifies the mechanism (passing a token from a truncation marker). This distinguishes it from sibling tools like 'scrape' or 'crawl' which operate on whole pages, while 'fetchMore' is explicitly for continuing a truncated page.

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 clearly states the condition for use: when a page was truncated, pass the token from the truncation marker. It also implies it should be used to continue the same page. It does not explicitly name alternatives or state when not to use it, but the context is clear enough for an agent to make the right selection.

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