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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety and network scope are covered. The description adds the useful constraint that only public, English-edition, canonical-URL articles are handled, but it does not disclose anything about return shape or limits. With annotations carrying the safety profile, this is an appropriate 3.

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, zero filler, and the core capability is front-loaded ahead of the sibling routing. Every clause 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?

For a one-parameter fetch tool with an output schema (so return values need no prose) and annotations covering safety, the description plus structured fields leave nothing an agent needs missing in order to invoke 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?

Schema coverage is 100% and the single parameter is already described as a canonical Euronews article URL. The description adds the meaningful 'English-edition' qualifier, which is an extra constraint beyond the schema, though it stops short of showing URL syntax or examples.

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 (Fetch) plus the exact resource (public Euronews article metadata and body paragraphs) and the required input form (canonical English-edition url). It also explicitly names the sibling tools it is not, so an agent can distinguish it without opening any schema.

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?

Explicitly routes the agent: euronews_headlines for story lists, euronews_sections to discover sections, euronews_news for the general feed. This is a clean when-to-use-this-vs-alternatives mapping with the selecting condition stated for each.

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