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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, covering the safety profile. The description adds context about the return payload (sources, confidence, ethics score, etc.), which is useful for understanding what the tool provides beyond the schema. No additional side effects are mentioned, but with read-only annotations, this is acceptable.

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?

One sentence, front-loaded with the core action ('Fetch one structured agent-news event by event_id'), followed by a concise list of included content. No wasted words and the structure is clear.

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 simple read-only get-by-ID tool with an output schema and full annotation coverage, the description adequately explains what the tool does and what it returns. It is complete enough without needing to discuss edge cases or error handling, as those are covered by the schema and standard behavior.

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 fully documents both parameters. The description merely repeats that it fetches by event_id and adds no extra meaning for agent_id or the parameters. Baseline score of 3 is appropriate when the schema does the heavy lifting.

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?

The description uses the specific verb 'Fetch' and clearly identifies the resource ('structured agent-news event') and the key identifier (event_id). It distinguishes from sibling tools like get_article by referencing agent-news events and listing included fields such as sources, confidence, ethics score, and agent voice score.

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?

The description implies usage when you need a specific event by ID, but it does not explicitly state when to use this tool over alternatives or provide exclusions. No alternative tools are named, so the guidance remains implicit rather than explicit.

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