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

Annotations already declare readOnlyHint and destructiveHint, so the safety profile is covered. The description adds meaningful behavioral context: credit costs, free repeats of known-empty lookups, the quote-then-confirm flow for size=1000, and the default limit. This goes beyond the annotations without contradicting them.

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 terse sentences: purpose, cost, quote note, and return shape. Everything earns its place, and the most important information is front-loaded. No filler or unnecessary repetition.

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 moderate-complexity tool with no output schema, the description covers the returned fields, default limit, total_count, pricing tiers, empty-result behavior, and the confirm_quote_id workflow. An agent has enough information to invoke the tool and interpret its result 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%, so the baseline is 3. The description adds value by linking size to credit costs, clarifying the confirm_quote_id handshake for size=1000, and confirming the limit default in the return description. This is useful semantic context beyond 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 opens with 'A target's pages ranked by number of backlinks' and lists the specific fields returned (backlinks, referring domains, broken links, page rank, first seen), making the operation clear. It does not explicitly name sibling tools to differentiate, but the focus on 'pages' is enough to separate it from related backlinks tools.

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 intended use case is implied by 'A target's pages ranked by number of backlinks' but no explicit when-to-use or alternative tools are mentioned. Operational guidance covers pricing and quote confirmation, yet there is no selection guidance among the backlinks_* siblings.

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