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

Annotations already declare readOnly/idempotent/non-destructive, and the description adds context they cannot carry: a 150 requests-per-minute account-wide limit, a 15-second minimum poll interval, the pollAfterSeconds return field, and the meaning of an empty result. That is exactly the operational context an agent needs to avoid hammering the endpoint.

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 sentences, front-loaded with what is returned and followed by polling cadence and termination condition. The 'minutes, not seconds' clause is short and directly supports the polling guidance rather than padding.

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 output schema, the description still surfaces the critical return field (pollAfterSeconds) and the empty-list terminal state, plus rate limits and scope. An agent can poll correctly and know when to stop without further documentation.

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% (limit defaults to 50; offset references nextOffset), so the schema carries the parameter burden. The description adds nothing about limit/offset, which is acceptable at this coverage level but earns only the baseline.

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?

Names a specific verb (list) and a tightly scoped resource: files queued for encoding or currently encoding, with progress. The scope wording ('right now', 'with its progress') separates it from siblings like livereacting_list_media or livereacting_get_import_status without needing to name them.

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?

Gives concrete usage conditions: poll no more often than every 15 seconds, use pollAfterSeconds, and stop when the list is empty ('nothing left to wait for'). It does not explicitly name an alternative tool for non-encoding status checks (e.g. get_import_status), so it falls short of a full when/when-not/alternatives statement.

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