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

Annotations already declare the write profile (readOnlyHint=false, idempotentHint=false, destructiveHint=false, openWorldHint=true), so the bar is lower. The description still adds non-obvious context the annotations do not: a hard cap of 50 items per request and a Builder-tier authorization requirement.

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?

Two short sentences, zero filler, with the capacity limit and the tier gate front-loaded where an agent will read them first.

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, yet the description says nothing about what comes back for a bulk write, which is the key open question: whether one failed URL aborts the batch or partial results are returned. For a 50-item mutation tool this is a meaningful omission.

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 each nested field (url, expires_at, max_clicks, custom_slug) is documented in-schema, so the baseline applies. The description adds no per-item meaning beyond the batch-size ceiling already implied by "up to 50".

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 states a specific verb and resource ("Create ... short URLs") and scopes it with "up to 50 ... in one request," which implicitly distinguishes it from the single-URL sibling shorten_url. It stops short of naming that sibling explicitly, so an agent must infer the batch-vs-single split.

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 one concrete usage precondition ("Builder tier required"), which tells the agent about a plan gate. It offers no explicit when-to-use-vs-alternative guidance, such as directing single URLs to shorten_url or explaining failure handling for oversized batches.

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