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

Annotations already cover read-only, open-world, idempotent, non-destructive, but the description adds what those can't: the exact returned payload shape, the no-login/public-site constraint, and an explicit honesty boundary that the grade measures visibility, not recommendation likelihood. That is genuine behavioral context beyond structured fields.

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-loads the purpose, then the sub-checks, then the trigger conditions, then the caveat — a sensible order. It is on the long side, and the enumerated return-field list and honesty paragraph make it dense, but each part serves a distinct decision the agent must make.

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?

There is no output schema, yet the description lists the returned keys (domain, grade, score, headline, readability, structure, legibility, posture, findings, remediation), so an agent knows what comes back. Combined with single-parameter input and clear trigger guidance, nothing needed to call it 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?

Schema coverage is 100% and already documents the domain format (no protocol or path). The description contributes the additional constraint that it must be a public website requiring no login, which meaningfully bounds which values are valid 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?

States a specific verb (check) and a precisely scoped resource: how legible and citable a business website is to AI answer engines, with an A-F grade. It enumerates the four sub-checks (crawler readability/JS rendering, structured data, Q&A content, crawler permissions), which clearly separates it from siblings like get_my_ai_visibility_coverage and plan_ai_visibility_fixes.

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 trigger conditions: someone asks whether AI/ChatGPT can find or read their business, mentions 'AI SEO'/answer-engine optimization, or wants a grade. Also states eligibility ('any public website — no login required'). It stops short of naming the sibling tools it supersedes or excludes (e.g. the coverage/plan tools), so it is clear context without full alternative routing.

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