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

Annotations already provide read-only, idempotent, and non-destructive hints. The description adds valuable context: each URL is independently validated, returns its own extraction/receipt/error, and the batch does not gain extra permissions. This goes beyond the schema and annotations without contradiction.

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, each carrying distinct information. The limit and scope are front-loaded, and there is no filler. Every word earns its place.

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 the simplicity (one array parameter) and the presence of annotations covering safety and idempotency, the description covers the essentials: batch size, public access, independent handling, and return types (extraction/provenance/error). It could be slightly more explicit about the exact output structure, but for a bounded fetch tool it is close to complete.

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 baseline is 3. The description adds meaning beyond the schema: it specifies 'public' URLs (a restriction not in the schema) and notes that each URL is independently handled, clarifying the batch behavior. This warrants a 4.

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 ('Fetch'), a resource ('up to five public HTTP(S) URLs'), and a mechanism ('in one bounded request'). It distinguishes from siblings by emphasizing the multi-URL batch nature, and mentions per-URL 'provenance receipt' which sets it apart from a simple read.

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 implies usage for multiple URLs by stating the batch limit and bounded nature. It doesn't explicitly name alternatives like fetch_url for single URLs, but the context is clear enough. There is no exclusion statement, so a 4 rather than 5.

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