get_v1_media_by_id

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds genuinely non-structured context: this is a live request to TikTok and it is billed per call, which an agent needs for cost/rate decisions. It does not, however, describe failure modes or rate limits.

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, each with a distinct job (purpose, selection rule, related tool/return, cost), front-loading the identifier requirement before the routing guidance.

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?

Covers what it returns, which sibling to use instead, which sibling to use next, and the billing/network reality, with no output schema needed since the return is described. Nothing an agent needs to call it correctly is missing.

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 0%, so the description must carry the burden; it characterizes the id as numeric and as coming from another tool, which clarifies the ^\d{19}$ pattern the schema only encodes silently. It stops short of stating the 19-digit format or example, but adds real meaning.

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?

States a specific verb and resource ('Get a TikTok video by numeric video id') and immediately differentiates itself from the sibling get_v1_media_by_url. An agent can pick the right tool without opening either schema.

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?

Explicit when-to-use ('when you have the id from another tool') and when-to-use-the-alternative ('use get_v1_media_by_url when you have a link'), plus a routing hint to get_v1_media_comments_by_id for comments. Nothing is left to inference.

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