External links

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

The description explicitly states 'Read-only,' which is consistent with the readOnlyHint annotation. It goes beyond annotations by detailing what each report returns (sample links with source page, target URL, discovery date, plus total count; time series of total count over time). This adds useful behavioral context without contradicting structured data.

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 description is concise and well-structured, with a clear opening statement followed by two bullet points for the report types. Every sentence provides useful information, and the format is easy to scan.

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?

Given the relatively simple tool (read-only, no output schema), the description covers the essential context: what the tool returns for each report type. It lacks detailed response structure or error handling, but that's not critical for a read-only tool with well-defined report outputs.

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 100%, so the baseline is 3. The description adds some context by clarifying that 'limit' and 'offset' apply only to report='samples' and that report='history' returns a time series, but this information is already present in the parameter descriptions. The description reinforces defaults but doesn't significantly augment the schema.

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 clearly states the tool's purpose: 'Inbound (external) links pointing to the host — the backlinks Yandex knows.' It uses a specific verb ('get') and resource ('external links') with clear scope, and distinguishes itself from siblings by focusing on backlinks, which no sibling tool covers.

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?

The description provides clear context on when to use the tool and how to use it, explaining the two report modes ('samples' and 'history') with their respective outputs. It doesn't explicitly mention alternatives, but since no sibling tool provides external link data, this is not a significant gap.

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