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 meaningful context beyond that: results are 'newest' and 'public', and the topic argument has a cross-tool provenance dependency on politico_categories. It does not mention pagination, but with an output schema present that gap is minor.

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 the core action, then the argument constraint and the sibling routing. No 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?

Purpose, the single parameter's valid source, and disambiguation against all three relevant siblings are all covered, and an output schema exists so return values need no explanation. Nothing required for a correct call is missing.

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 schema already says 'Politico section slug'. The description goes further by constraining provenance ('must be a slug returned by politico_categories'), which prevents an agent from passing an arbitrary string — genuine value 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 and resource with scope: 'Fetch the newest public Politico story items from one section archive.' It explicitly separates itself from politico_headlines, politico_article, and politico_author, so an agent can route correctly without inspecting sibling schemas.

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 when-to-use routing ('use politico_headlines for current headlines, politico_article for one story, or politico_author for a profile') plus a precondition that topic must be a slug returned by politico_categories. Both the alternative and the selection condition are named.

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