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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is covered. The description adds genuine value beyond them: it pins the operation to exactly one public HTTPS page, and explicitly disclaims what the result does NOT mean (indexing, crawler treatment, ranking) and that redirect history is unobserved. These caveats prevent over-interpretation of the output, which is exactly the kind of context an agent needs for an SEO-flavored inspection.

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?

Three tight sentences, front-loaded with the core action and immediately followed by the two caveats that matter most. No filler, no repetition of the title or schema, and every sentence carries a distinct constraint.

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, and annotations cover the safety profile. The description fills the remaining gap with scope and interpretation limits. Minor omissions such as rate limits or behavior on pages that fail to fetch are the only things keeping this from a 5.

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%; both sourceUrl and targetUrl are documented in the schema, including 'ignoring fragments' for the target. The description restates the public-HTTPS constraint but adds no format, normalization, or matching-syntax detail beyond what the schema already supplies, so the baseline of 3 applies.

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 names a specific verb+resource pair: 'fetch one public HTTPS source page' and 'report matching anchor markup for a public HTTPS target, including observed rel tokens.' This is precise enough that an agent knows exactly what the call produces. It does not explicitly contrast itself with any sibling (e.g. toolfound_share_preview or toolfound_campaign_links), which keeps it short of a 5.

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?

Usage is implied by the stated purpose but never spelled out: there is no 'use this when you need X' and no named alternative. The only routing-flavored text is a negative scope note ('does not establish indexing, crawler treatment, or ranking impact'), which constrains interpretation rather than telling the agent when to pick this tool over another.

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