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

Annotations already declare readOnly, idempotent, and closed-world, so the safety profile is covered. The description adds real behavioral context beyond them: results are limited to episodes referenced by a published digest, and the echoed ``lang`` field reveals what was actually served ('' = English original), which prevents an agent from misreading a fallback response.

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 tight sentences, with the payload description and the digest scoping front-loaded before the optional parameters. Slightly dense due to the parenthetical translation clause, but no sentence is wasted.

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?

An output schema exists, so return values need no prose explanation, and the description covers scope and translation fallback well. The remaining gap is failure behavior — what happens when ``eid`` is not in a published digest or ``lang`` has no translation — which is not stated, though the echo note mitigates the latter.

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 earns above baseline by explaining the echo semantics of ``lang`` (the payload reports what was served, with '' meaning the English original) and the disambiguation role of ``digest`` for multi-week episodes — semantics the schema text does not carry.

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 opening sentence enumerates exactly what is returned (title, show, summary, full transcript) for a single episode, and the second sentence states the scoping constraint to published digests. It is distinguishable from get_digest and list_digest_episodes, though it does so by describing payload and scope rather than by naming the siblings explicitly.

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 conditional guidance for two of the three parameters ('Pass digest when an episode spans more than one week', 'Pass lang ... when the translations exist'), which is genuinely useful. However, it never says when to choose this over list_digest_episodes or get_digest, so an agent must infer the selection rule; usage is implied rather than stated.

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