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

Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=false), so the description's job is to add context. It does: it discloses the implicit ownership filter (only the caller's own meetings), the recency filter (only ones still running), and the return content (participant count per meeting). No pagination, ordering, or empty-result behavior is mentioned, which is the only notable gap.

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?

One sentence, front-loaded with the action and resource, with the two filters and the return content packed in without a wasted clause. Nothing is repeated from the title or annotations.

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?

With no input parameters and no output schema, the description carries the burden of explaining what comes back, and it does so partially by noting the per-meeting participant count. It does not describe ordering, volume, or what an empty result means, but for a simple read-only list that is a minor omission.

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?

The tool takes zero parameters, so there is nothing for the description to disambiguate. The baseline for 0-param tools is 4, and the description appropriately spends no words on parameters.

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 a specific verb and resource ('Lists ... meetings') and adds two scoping qualifiers: it is limited to the signed-in person's own meetings and to those 'still running'. That is enough for an agent to distinguish it from a generic meeting-listing call. It stops short of naming the obvious sibling (list_recordings) as the contrasting alternative, so it is clear but not differentiated from 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?

'still running' implies the when-to-use condition (live/ongoing meetings), but the description never states it as guidance, nor does it say when not to use this tool or which sibling to reach for instead. The usage boundary is inferable rather than declared.

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