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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint false. The description adds useful behavioral context beyond those annotations by explaining the tool is scoped to the connected workspace/site and that a domain parameter is only needed for competitor analysis. It does not contradict the annotations and gives the agent operational expectations.

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 three sentences with no filler: purpose and data types, usage guidance with a sibling alternative, then scoping/operational note. It is front-loaded with the most decision-relevant information and every sentence earns its place.

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 rich annotations, complete parameter schema with detailed enum descriptions, and the existence of an output schema, the description covers everything an agent needs: purpose, when to use, which sibling to choose instead, and how the tool is scoped. There is no missing information that would prevent correct invocation or selection.

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 schema already fully documents all five parameters, including the action enum and domain omission behavior. The description adds little parameter-level detail beyond reinforcing that domain is optional. Baseline 3 is appropriate because the schema, not the description, carries the parameter documentation burden.

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 uses a specific verb ('Read') and names the exact resource ('backlink profile of your own site or any competitor'), then lists concrete data types included: referring domains, anchor-text distribution, link velocity, and link-prospect intersects. It also distinguishes itself from serp_competitors by noting that tool is for rankings. This makes the tool's purpose unmistakable.

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 explicitly states when to use the tool ('for authority and link questions') and names the alternative for rankings ('use serp_competitors'). It also clarifies the default scope and that no domain parameter is needed unless analyzing a competitor. This is clear, actionable guidance with an explicit exclusion.

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