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

Annotations already declare this a safe, idempotent read, so the bar is lower, but the description still adds real behavior: URLs are withheld unless the link was opened, results are limited to open plus recently-ended links, ownership is required, and the call costs $0. It also enumerates the returned fields (mode, state, caps, use, expiry, availability, limits), which matters since there is no output 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?

The scoping information and the URL-redaction caveat are front-loaded in a single dense sentence, followed by a short gloss on `availability`/`limits` and the ownership and cost notes. It is compact with no filler, though jargon like 'caps', 'use' and 'born with' costs a little clarity.

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?

For a one-parameter read with no output schema, the description covers result scope, redaction behavior, authorization, cost and the shape of the returned object, which is nearly everything an agent needs to call it correctly. The only real gap is the meaning/format of project_id and what 'caps' actually contain.

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?

With a single required parameter at 0% schema coverage, the description must carry the meaning, and it only implies that the piece referenced ('a piece') is the project_id target without saying so or giving a format. The rest of the sentence is spent on return values rather than the input, leaving the sole parameter thinly documented.

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 specific verb and resource ('Lists the upload links of a piece') and further narrows the scope to open links plus those that ended in the last 7 days, so an agent knows exactly what set is returned. It does not name a sibling (e.g. open_channel / close_channel) to contrast against, so it stops short of full sibling differentiation.

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 implied rather than stated: an agent can infer this is the inspection step before opening a link, helped by the mention that `availability` says whether the account can open one and `limits` the caps a new link is born with. The only explicit constraint is 'Only the piece's owner'; there is no explicit when-not or named alternative such as open_channel.

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