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

Annotations already declare readOnlyHint=true, so 'Read-only observability' largely restates structured data. The description does add the pagination behavior (cursor-based listing), but says nothing about ordering, rate limits, or retention/visibility rules for events. With annotations covering the safety profile, this is adequate but thin.

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?

Three terse clauses with the core purpose front-loaded, followed by the read-only nature and the underlying API endpoint. Nothing is wasted and the API mapping is genuinely useful for cross-referencing.

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 zero-required-param list tool with full schema coverage and no output schema, the description covers calling mechanics but omits what an event record contains and how results are ordered. Complete enough to invoke correctly, not complete enough to interpret results.

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%, and the schema already documents limit, starting_after, and ending_before with cursor semantics. The description's mention of cursor pagination matches but adds no format, default, or ordering detail beyond the schema, so the baseline of 3 applies.

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 ('List notification delivery events') and adds the pagination mode, which cleanly distinguishes it from the singular sibling magicbell_get_event. It does not explicitly name the sibling or contrast them, so it falls short of a 5.

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?

'Read-only observability' implies the usage context (inspecting delivery outcomes) but gives no when-to-use vs. when-to-use magicbell_get_event, and no prerequisites. Usage is inferable rather than stated.

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