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

Annotations already declare readOnlyHint and openWorldHint, so safety and external-fetch behavior are covered. The description adds a genuine content-scope constraint beyond annotations – photo galleries and sponsored partner stories are rejected – but does not mention rate limits, auth, or redirect handling.

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 and waste-free: the first defines the tool and its scope, the second routes to alternatives. 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?

An output schema exists, so return-value explanation is unnecessary; the description nonetheless summarizes the payload (metadata, section, body paragraphs), states scope limits, and points to discovery siblings. Complete for an agent to call 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 url parameter is already documented as 'Canonical Daily Star (UK) article URL'. The description reinforces the 'canonical url' requirement but adds no syntax or format detail beyond the schema, 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 verb (Fetch) and resource (Daily Star UK article metadata, section, and body paragraphs), and even enumerates the return content. It is clearly distinguishable from sibling tools like dailystaruk_headlines and dailystaruk_sections.

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 names two alternatives and their selection conditions ('dailystaruk_headlines to discover stories or dailystaruk_sections to choose a section'), and adds an exclusion rule (galleries and sponsored stories rejected). Nothing is left to inference.

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