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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is covered. The description adds a genuine behavioral trait not in the annotations: results are returned 'newest first'. It says nothing about pagination behavior, defaults, or how unread state is represented, so it adds modest value over the structured fields.

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, front-loaded with the core framing ('Your inbox') followed by ordering and content scope. Every clause carries information and there is no filler.

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?

The tool is simple (two optional params, no nesting) and an output schema exists, so return values need not be explained. The description covers identity, content scope, and ordering, which is adequate for an agent to call it correctly. Only the missing routing to mark_notifications_read keeps it from a 5.

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%, with both limit and unread_only documented in the schema itself, so the baseline is 3. The description adds no parameter-level detail beyond the schema (e.g., it never mentions the limit cap or the unread filter), but it also has no obligation to.

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 names the resource (notifications), characterizes it as 'your inbox', and enumerates the content types (assignments, changes to your items, mentions) plus the ordering (newest first). This is far more specific than a tautology and helps distinguish it from list_todos or my_work. It stops short of explicitly naming a sibling it is not, so it doesn't reach 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?

There is no explicit when-to-use or when-not-to-use guidance, and no reference to the closely related sibling mark_notifications_read, which an agent would need to distinguish viewing from mutating notifications. The phrase 'Your inbox' only weakly implies the usage context, which is the definition of implied rather than stated guidance.

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