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

Annotations already cover the safety profile (readOnly, non-destructive, openWorld), so the description's job is to add context — and it does: the TikTok 'sent' status until the video is named, and that MCP Apps hosts render the result as a card. That is genuinely useful behavior an agent could not infer from structured fields.

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?

Front-loads what is returned before the routing hint and the optional-parameter note; almost every sentence carries information. Slightly dense with the TikTok and MCP Apps asides, but none is 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?

With no output schema, the description must convey the return shape, and it does — per-network lines with location, status, views, likes and link. Combined with the optional-param rule and the status caveat, an agent has enough to call and interpret it.

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% and the single postId description already says 'Omit for the most recent published post.' The description restates that same fact without adding format, ID source, or error semantics, so this is the baseline 3.

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: one post's results, itemized one line per network with named fields (where it went, status, views, likes, link). It explicitly distinguishes itself from get_metrics, so an agent can route 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?

Explicitly frames the selecting question ('how did my post do?') and names get_metrics as the wrong tool for it, which is clear when-to-use guidance. It does not, however, differentiate against get_post or list_posts, so a sibling ambiguity remains.

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