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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds valuable behavioral context beyond that: it discloses that responses include 'the upstream's own restricted-access signals,' which is important for a news article tool and not captured by annotations.

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, information-dense sentence with no wasted words. The core resource and content type are front-loaded, and the additional nuance about restricted-access signals is placed at the end without disrupting clarity.

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 output schema exists and annotations cover read-only/open-world behavior, the description is nearly complete for a simple 1-parameter tool. It states what is returned (metadata and body paragraphs) and mentions restricted-access signals, though it could clarify usage relative to sibling tools.

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%, so the single url parameter is fully documented in the schema. The description adds no new syntactic or format details beyond restating 'canonical article URL,' so the baseline of 3 applies.

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 resource (SCMP article) and content (public metadata and body paragraphs) from a canonical URL, clearly distinguishing it from list-oriented siblings like headlines. However, it does not explicitly name an alternative tool or scope boundary, so it falls short of the explicit sibling differentiation seen in top-scoring definitions.

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 gives no when-to-use or when-not-to-use guidance. It implies the tool requires a canonical article URL but does not mention alternatives (e.g., scmp_headlines for lists) or prerequisites beyond the schema. An agent must infer usage context entirely.

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