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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description still adds value beyond that by disclosing what the payload contains: current progress and the provenance of the date verification, which is non-obvious and shapes how the result should be trusted.

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, no filler, with the identifying key and the notable payload contents both front-loaded. Every clause 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 tool with no output schema, the description gives enough about the lookup key and the return contents to call it correctly. Missing only explicit guidance on failure behavior for an unknown slug and on when to prefer a search sibling.

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 already includes an example value, so the baseline is 3. The description goes further by defining a slug as the last part of the event's URL, which tells an agent how to derive the value from a link rather than only what shape it takes.

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 (retrieve details) and resource (one event) plus the lookup key, so it is clearly distinct from the list-style siblings search_events and upcoming_events. It does not name a sibling explicitly, but the singular 'one event by slug' makes the boundary obvious.

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 slug-based lookup implies when to use it (you already know which event you want), but the description never says so outright and never points to search_events for discovery. An agent must infer the routing rule.

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