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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds useful scope context beyond the annotations by clarifying that output is the unfiltered general top-story stream (headline items only, not bodies), though it says nothing about result count, pagination, or freshness.

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?

Front-loads the core action before the routing sentences, and every sentence carries information. It is slightly heavier than strictly necessary since three sibling references are packed in, but none are filler.

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 parameterless, read-only feed tool with an output schema covering return values and annotations covering safety, the description supplies everything an agent needs: what it fetches, its scope versus siblings, and how to proceed for other needs.

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?

The tool takes zero parameters, so per the baseline there is nothing for the description to disambiguate. No parameter semantics are needed or missing.

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 and resource ('Fetch 9to5Mac top stories from the public feed') and explicitly scopes it as the general top-story stream rather than a filtered one. It names the sibling ninetofivemac_headlines as the section-specific alternative, so an agent can distinguish it 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?

Gives explicit routing: use this for the general stream, ninetofivemac_headlines for section-specific lists, ninetofivemac_sections to discover slugs, and ninetofivemac_article when a single story body is needed. The when-to-use and when-not-to-use conditions are fully specified.

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