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

Annotations already declare readOnly/openWorld/idempotent/non-destructive, so the safety profile is covered. The description adds real behavioral boundaries beyond that: it does not promise an effect on AI Overviews, does not query AI engines, reads public pages only, and reports the date the pages were read. Useful scoping context, though it does not discuss failure modes like unreachable or blocked pages.

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?

Front-loaded with the action and usage trigger, and every clause carries information. It is on the long side with some mildly redundant expectation-setting ('does not promise an effect on AI Overviews') and the note about a cited public post, but no sentence is clearly 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?

An output schema exists, yet the description still sketches the return shape (pass/warn/fail per part, evidence URL, fix, read date), and it covers the input constraint, usage triggers, and exclusions. Nothing an agent needs to select or invoke this tool correctly is missing.

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?

There is a single parameter with 100% schema description coverage, so the schema already documents the domain format and the public-pages-only constraint. The description's 'Pass the domain' adds nothing beyond the schema, which is the expected baseline when the schema does the work.

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?

States a specific verb and resource ('Checks the site's AI instructions files and page') and enumerates exactly what is inspected: llms.txt, llms-full.txt, the AI instructions page, home-page links, and factual match against the site's own name/products. This clearly separates it from the sibling generate_ai_instructions, which creates rather than verifies.

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?

Gives explicit triggering conditions ('Use this when the user asks whether a site publishes...') plus hard exclusions ('Do not use it for private addresses or to collect contact details' and 'Public pages only'). It does not name a sibling alternative such as generate_ai_instructions, which keeps it from a full 5.

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