on_this_day

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

No annotations are provided (empty), so description carries burden. It discloses that unsupported languages cause 404, and returns a note, but doesn't mention rate limits, error handling, or what happens on no events. It provides some transparency but not comprehensive.

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?

Concise, with clear sections for note, args, and returns. Front-loaded with purpose. No wasted sentences; every sentence adds value.

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 tool with 2 optional params and no output schema, the description adequately covers behavior, limitations, and return structure. It could mention the date context (implicitly today's date) but overall complete for its complexity.

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 0% (no descriptions in schema), but the description explains both 'lang' and 'limit' with defaults and purpose. It adds meaning beyond schema, so it compensates somewhat. However, it doesn't specify format constraints like language code pattern or max limit value.

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 clearly states it returns Wikipedia's curated 'on this day' events, with a specific resource (Wikipedia API) and verb (get events). It doesn't explicitly differentiate from siblings like 'web_read' or 'rss_read', but its purpose is distinct and clear.

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?

It implies usage for fetching historical events for a given date, but doesn't provide explicit when-to-use vs alternatives. It mentions language support limitation, which is useful, but no clear exclusions or alternative tools.

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