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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered. The description adds the useful behavioral note that it returns the 'full record' (contrasting with the partial list view), but says nothing about return format, caching, or missing-slug behavior.

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?

A single front-loaded sentence with zero filler; the lookup key follows immediately after the purpose. Nothing is wasted.

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 no output schema and a simple read tool, the description is close to sufficient, but it leaves the lang parameter unexplained and does not state that the slug originates from list_news. Adequate but with recognizable gaps.

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 carry the load, but it only explains the 'slug' parameter and gives no semantics for 'lang'. The enum values and default are visible in the schema, but the description never confirms that lang selects the localized article (and what happens with unsupported translations).

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') and resource ('full record for a single news article'), with the lookup key ('by its slug') made explicit. The word 'single' implicitly separates it from the sibling list_news, though the sibling is never named.

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 phrase 'by its slug' implies the caller must already have a slug (presumably from list_news), so usage is implied rather than stated. There is no explicit 'use this instead of list_news when...' routing guidance or precondition statement.

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