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

Annotations already declare readOnlyHint and openWorldHint, so safety is covered. The description adds real value beyond them: it explains that only public, server-rendered content is returned and that 'account-gated content is not bypassed', which sets accurate expectations about the paywall/limit 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?

Two sentences, both front-loaded: the capability and its scope come first, the sibling routing second. No filler and every clause carries information.

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?

An output schema exists, so return values need no explanation. Combined with annotations covering safety and the description covering what content is fetched and the gating limitation, an agent has everything needed to call this 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 description coverage is 100% and there is a single parameter, so the schema already documents the url fully. The description mostly repeats 'canonical cnbc.com url', adding only the 'dated' nuance; baseline 3 is appropriate.

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 (CNBC article metadata and server-rendered body paragraphs) with scope qualifiers: 'public', 'canonical dated cnbc.com url'. It also names the sibling tools it is not, so an agent can distinguish it from cnbc_headlines/cnbc_categories/cnbc_author 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?

It routes the agent to three alternatives (cnbc_headlines to find stories, cnbc_categories to browse topics, cnbc_author for a writer's profile), which clarifies the discovery-vs-fetch split. It does not, however, state the explicit condition for using this tool (i.e. 'when you already have an article URL'), leaving that to inference.

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