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

Beyond the readOnly/idempotent annotations, the description reveals ordering (newest first), return behavior (unread_count alongside the page), pagination semantics (pagination.total, has_more, offset until has_more is false), and the maximum limit. This is useful behavioral detail the annotations do not provide.

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 concise sentences front-load the core purpose, then cover return value and pagination. Every sentence earns its place with no filler or repetition of schema details.

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 has 7 optional parameters fully described in the schema and an output schema. The description supplies the missing behavioral context: scope, ordering, unread_count, and pagination. An agent has everything needed to call it correctly.

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%, so the baseline is 3. The description adds value by explaining how to paginate with offset until has_more is false and emphasizing the max limit of 200, which reinforces the schema's parameter info with operational guidance.

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 states a specific verb and resource: 'List the signed-in user's own Matrix notifications, newest first.' It clearly scopes the tool to one's own notifications and explicitly says there is no way to read anybody else's, distinguishing it from any other notification or retrieval tool.

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 description gives clear context: it lists the signed-in user's own notifications and notes that unread_count is included so a separate unread-count call is unnecessary. It does not explicitly name alternative tools or state when not to use it, but among the notifications siblings the usage context is clear.

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