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

Annotations already declare readOnlyHint and openWorldHint. Description adds valuable behavioral details: 'Lean mode — no evidence bundle stored, no bundle_id returned' and mentions return of final_url after redirects.

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?

The description is concise (4-5 sentences) and well-structured: action, mode, usage guidance, return format, example prompts. Every sentence adds value.

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 simple tool with one parameter, output schema, and annotations, the description is fully complete: it explains purpose, behavior, return value, and usage examples.

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% with a good description and example. Description doesn't add significantly beyond the schema for the parameter itself, but example prompts provide helpful usage context, justifying a slight bonus above baseline 3.

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 clearly states it fetches a public HTTPS URL and returns extracted text and metadata. It explicitly distinguishes from siblings by naming alternatives: url.summarize, url.qa, url.translate, document.extract_text.

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?

Explicitly says when to use (raw text extraction from web pages and documents) and when not (summaries, Q&A, translation, base64 uploads), with specific alternative tools mentioned.

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