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

Beyond the readOnlyHint/openWorldHint annotations, the description discloses meaningful behavior: the language fallback rule ('returns the requested language when the video has it, otherwise the first track'), the presence of an isAutoGenerated flag, and a per-call credit cost. That is real operational context an agent could not infer from the schema.

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?

Four short sentences, with the return shape and fallback rule front-loaded and the cost note last. The leading 'Video transcript.' restates the title and could be dropped, but the rest is dense with no filler.

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 describing what comes back (one text block plus timed cues, an isAutoGenerated flag). Combined with the fallback rule and cost, an agent has enough to call it correctly; only the undocumented cache_max_age param is left uncovered.

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 67%, so the schema documents url and language reasonably well. The description adds one genuinely useful semantic about `language` (silent fallback to the first available track), but `cache_max_age` has no description anywhere and the language fallback is stated as runtime behavior rather than as a parameter contract.

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 gives a clear verb and resource ('A PeerTube video's captions as one text block plus timed cues') and identifies the platform, which separates it from the many other *_transcript siblings. It does not explicitly name a sibling alternative, but the platform prefix plus the concrete output shape makes the target unambiguous.

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?

Usage is only implied: it says the tool returns captions for a video, so an agent can infer it should be called when a transcript is wanted. There is no explicit 'use this when X, use peertube_video when Y' guidance and no stated prerequisite about the video having caption tracks.

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