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

Annotations already cover safety (readOnlyHint=true, destructiveHint=false, openWorldHint=true), and the description adds genuinely useful context beyond them: this is bounded, cannot be paged, makes no additional provider calls, and execution is blocked until costs are approved. It also warns that proprietary rankings are not Google ratings or measured traffic, which prevents misinterpretation of the results.

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?

Four short sentences, front-loaded with the core identity, and no filler. The telegraphic phrasing ('Preserve target kind and provider scope') is terse to the point of ambiguity, but nothing is wasted.

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 nested-object tool with no output schema and zero parameter documentation, the description covers provenance and cost gating well but leaves the response shape (what a 'network' record contains) and two of three parameters unexplained. Enough to avoid misuse on cost, not enough to call confidently.

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 0% across three parameters, so the description carries the full burden, yet 'Preserve target kind and provider scope' only gestures at the target.kind enum and says nothing concrete about the networkType enum (IP vs SUBNET) or the limit cap of 20. The agent must read the schema to learn anything usable.

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?

Names the resource (referring networks) and the source (Nexscope backlink index), which tells an agent this is a backlink-graph query rather than a keyword or SERP tool. However, 'projection' is unexplained jargon and the description never distinguishes this from the close sibling nexscope_seo_referring_domains, so the agent must guess which of the two to call.

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 only usage-ish statements are negative constraints ('No pagination or additional provider calls', 'Unapproved costs prevent execution'). There is no when-to-use condition, no prerequisite state, and no routing to the obvious alternative nexscope_seo_referring_domains or the broader backlink tools.

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