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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds real behavioral context beyond that: the 50-link cap and the failure mode (returns why a link could not be read), which an agent otherwise would not know.

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?

One tight sentence that front-loads the operation and its output before pivoting to usage. Minor run-on in the second clause but no wasted sentences.

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?

An output schema exists, so return values need not be described here, yet the description still previews the result shape and error case. Combined with annotations covering read-only/open-world behavior, an agent has everything needed to invoke it correctly.

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 parameter is fully documented in the schema itself (type, URI pattern, min/max items). The description's 'up to 50 links' simply restates the schema's maxItems, so it adds little beyond the structured field.

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 (reads) and resource (links), and enumerates exactly what is returned per link (title, description, site, kind). This is distinct from the sibling make_set/read_set operations, which the description implicitly separates by positioning this as a pre-step to making a set.

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?

Gives concrete when-to-use contexts: 'before making a set, to check the links work and describe them, or to see what links someone sent are about.' It does not name an alternative tool explicitly, but the usage contexts are clear enough that an agent knows when to reach for it.

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