Fetch multiple URLs

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

Annotations already declare readOnly, idempotent, open-world and non-destructive, so the safety profile is covered. The description adds genuinely non-obvious behavior: parallel execution, markdown normalization, reuse of the same handler/fallback chain, and a reduced per-URL output budget. It does not say how per-URL failures or partial results are surfaced.

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 sentences, front-loaded with the core behavior and batching cap, followed by the differentiator and the usage cue. No padding or redundant restatement of the name or title.

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?

With annotations, a complete input schema and an output schema, the description covers purpose, scale and routing well. The one meaningful gap for a batch tool is partial-failure semantics, which an agent may need before committing to ten URLs.

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 coverage is 100%, so every parameter including maxTier, noCache, maxLength and timeoutMs is already documented, which sets the baseline at 3. The description only adds that the length budget is smaller than the single fetch tool's, without giving the concrete value or explaining the tier/archive interplay.

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 and resource ('Fetch up to 10 URLs in parallel') plus the return format ('clean markdown'), and implicitly differentiates from the single-URL fetch sibling by calling out the smaller per-URL length budget.

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?

'Use after a search to pull several sources in one call' gives a clear triggering context, and the reference to 'the fetch tool' with a smaller per-URL length budget hints at when to prefer the single-URL sibling. It stops short of an explicit when-not-to-use rule or a blanket statement of alternatives.

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