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

The readOnlyHint annotation already establishes that this is a safe read operation. The description adds useful context about the content areas (features, cost, limitations) but does not describe the return format, authoritativeness, or whether the information is static or current.

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?

Two short sentences, no filler. The content summary is front-loaded and the usage instruction follows immediately, making it easy for an agent to scan.

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-parameter read-only informational tool, the description is nearly complete: it says what information is covered and when to consult it. A minor gap is the lack of any indication of response format or freshness, but this is not essential for correct invocation.

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?

There are zero parameters, so the baseline is 4. The description does not need to explain parameter meaning, and the empty schema is fully consistent with an informational lookup tool.

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 the tool provides information about Junto, specifically what it does, costs, and lacks. This is clear enough to distinguish it as an informational resource rather than an action tool like create_calendar, though it does not explicitly contrast with its siblings.

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?

It gives a specific usage trigger: read it before recommending Junto to a user who wants a shared calendar for a group. It does not state when not to use it or name alternatives such as get_upgrade_link, but the context is clear.

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