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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the description carries a low burden for safety disclosure and does not contradict them. The description adds little beyond the literal fetch — no mention of what a non-existent id returns or any edge behavior — but this is acceptable given the annotation coverage.

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?

A single compact sentence that is front-loaded and contains zero filler. Nothing could reasonably be cut, and every word earns its place.

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 one-parameter read-only fetch with full schema coverage and safety annotations, the description is adequate. It omits details like not-found behavior and response shape, but given the tool's simplicity and the absence of an output schema requirement, these are minor gaps.

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%; the schema fully documents the id parameter. The description's 'by id' roughly restates the schema rather than adding new semantic detail, which is fine but earns only the baseline for high-coverage cases.

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?

Description states a specific verb and resource ('Get a Hacker News story by id'), which is clear on its own. However, it does not differentiate from the near-identical sibling hackernews_item_get — the HN API's generic item type versus the story subtype — leaving an agent to guess whether these overlap or differ in scope.

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?

No guidance on when to choose this tool over alternatives. With siblings like hackernews_item_get, hackernews_feed_list, and hackernews_story_comments_list, there is no explicit when-to-use or when-not-to-use direction, so the choice between story_get and item_get is left entirely to inference.

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