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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so safety is covered. The description adds a useful output summary ('score /60 with per-check results and improvement tips'), but an output schema exists, so that value is partly redundant. It says nothing about which checks are performed or how the /60 is composed.

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 with the action and output front-loaded and the GEO parenthetical placed where it clarifies rather than clutters. No filler sentences.

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?

With annotations, an output schema, and a fully documented single parameter, the description covers what an agent needs to invoke it. The main remaining gap is that it never enumerates what GEO checks are scored, which would help an agent decide if this tool answers its question.

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?

Only one parameter, and schema coverage is 100% with the schema itself stating 'or full page HTML'. The description's '(or full HTML)' adds almost nothing beyond the schema. Baseline 3 applies since the schema does the heavy lifting.

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 (analyze/score) and resource (webpage <head> or full HTML) plus the exact domain (GEO signals). The purpose is unambiguous and doesn't overlap conceptually with nearby siblings like calculate_readability or security_headers_check, though it never names an alternative explicitly.

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 only implied: you infer you should call it when you have HTML and want a GEO assessment. The definition of GEO ('optimizing pages for AI-powered search engines') is context, not a when-to-use rule. No exclusions or named alternatives are given.

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