Fetch Page

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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is covered. The description adds that only *public* pages can be read and that output is text, which is genuine extra context, but it says nothing about auth requirements, rate limits, or failure behavior on non-public URLs.

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 short, front-loaded sentences with zero filler. The action and its scope come first, the input sourcing second.

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 single-parameter read tool with an output schema, annotations covering safety, and 100% schema coverage, nothing essential is missing. The description supplies the action, scope, and input provenance the agent needs to call it correctly.

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?

With one parameter at 100% schema coverage, the baseline is 3; the description goes slightly beyond the schema by specifying the URL's provenance ('returned by search'), which tells the agent how to source the value rather than just its type.

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 a public page as text'), which is clearly distinguishable from mutation siblings. It does not, however, differentiate itself from likely-overlapping siblings like extract or web-crawl, 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?

'Pass a URL returned by search' gives a precondition for the input, implying this tool follows a search step. But there is no when-to-use/when-not guidance versus the many search and extraction siblings, leaving the choice largely to inference.

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