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

The description adds substantial behavior beyond the annotations: no messages are sent, the tool is unaffected by plan or creation allowance, cancelled/completed reminders are excluded by default, and the delivery statuses carry precise semantics ('scheduled is not delivered', 'delivered means Telegram accepted the message, not that the owner read it', 'uncertain must not be treated as delivered'). That last point is exactly the kind of interpretation rule an agent cannot infer from readOnlyHint/idempotentHint.

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?

Front-loaded with the resource and returned fields, and each sentence carries information (scope, side-effect freedom, availability, default filtering, status semantics). The status-semantics sentence is dense and names values without naming the parameter they belong to, which costs a bit of scanability.

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?

There is no output schema, and the description compensates by naming the returned fields and the meaning of each delivery status, which is the main thing an agent needs to interpret results. The main gap is that pagination via limit/offset and total-count behavior are not described for what is a list endpoint.

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 0%, so the description must compensate: it does explain three enum values (scheduled, delivered, uncertain) and the default exclusion of cancelled and done, which effectively documents the status parameter. It says nothing about limit or offset, leaving pagination semantics entirely to inference from the bare numeric bounds.

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 the account owner's standalone and task reminders') and names the fields returned (text, scheduled time, delivery status), which no sibling tool does. It does not explicitly contrast itself with cancel_reminder or create_reminder, but the read-only listing scope differentiates it well enough in practice.

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?

'By default excludes cancelled and completed reminders' implies that a status filter is needed to see those, and 'available regardless of the plan or creation allowance' tells the agent it won't be blocked. However, there is no explicit routing guidance (e.g. 'use cancel_reminder to cancel', or which status value to pass to include completed items), so usage is only implied.

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