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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety and public-web behavior are covered. The description adds useful scope ('one page of recent articles') and notes a public profile, but does not describe rate limits, pagination beyond the page parameter, or whether an identifier is mandatory.

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, front-loaded with purpose and followed immediately by usage routing. No redundant or filler text; every clause carries selection-relevant 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?

For a read-only fetch tool with an output schema and strong annotations, the description covers purpose, inputs, and sibling alternatives well. It leaves a gap around what happens if neither slug nor url is supplied, since all three parameters are optional and the description only implies an identifier is needed.

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 schema already documents url, page, and slug in more detail than the description. The description mentions slug or url as alternatives and page as selecting the article page, but adds no syntax or behavioral detail beyond the schema.

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 ('Birmingham Mail author's public profile and one page of recent articles'), and explicitly distinguishes itself from sibling tools by naming birminghammail_headlines and birminghammail_article. An agent can identify the tool's scope without opening the 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?

Names the alternative tools and the conditions that select them: headlines for section stories, article for one story. It also explains that slug or url identifies the author and that page selects the article page, giving clear when-to-use routing.

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