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

Annotations already declare readOnly, idempotent and non-destructive behavior, so the description is not carrying the safety burden. It earns credit for adding genuinely new facts: a 6-hour refresh cadence and the negative scope statement that article text is never returned, which prevents an agent from misusing it as a content reader.

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 compact sentences with zero filler: the first front-loads the payload and returned fields, the second adds freshness and a usage caveat. Every clause carries information an agent can act on.

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 zero-required-parameter read tool with full schema coverage and no output schema, the description covers the returned fields, the freshness guarantee, and the content limit. Only minor gaps remain, such as ordering of results when limit truncates the list.

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%, including enum values for category and bounds for limit, so the baseline is 3. The description adds no parameter-specific meaning beyond the schema, and it is silent on the visitor_name parameter, which is unrelated to a read-only news fetch.

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?

"Get up-to-date headlines about AI" names a specific verb and resource and enumerates the source types (official labs, research feeds, news sites, developer blogs). It also lists the returned fields, so an agent knows exactly what it gets. It does not explicitly differentiate itself from siblings, though none of the listed siblings overlap in function.

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?

Usage is implied rather than stated: "Read the source for details" signals this is a headline/summary tool, not a full-text reader, which is useful routing guidance. There is no explicit when-to-use, when-not-to-use, or named alternative, and no mention of how it relates to other discovery tools.

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