Page extraction (paid)

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

Annotations already provide readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds valuable context: 'SSRF-safe', return elements (status, contentType, markdown|text), the 200KB cap, and the cost of $0.005. These are behavioral details beyond the annotations, giving agents essential information about limitations and side effects.

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 two sentences with no redundancy. It front-loads the key info (what it does), then gives the URL endpoint, cost, safety, return details, and usage guidance. Every sentence earns its place, and the critical usage note is placed at the end for context.

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?

This is a simple 2-parameter tool with a strong schema. The description covers the essential context: purpose, usage guidance, cost, safety, return structure, and size limits. No output schema exists, so the description appropriately explains what the agent will receive (status, contentType, content). Nothing critical is missing for correct invocation.

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 detailed descriptions for both parameters, so the baseline is 3. The description does not add extra meaning beyond the schema; it mentions format options but doesn't provide deeper semantic help. The schema already explains examples and preferences (e.g., prefer 'markdown'), so no deduction is needed, but there's no added value either.

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 states the specific verb 'fetch' and resource 'public URL', explains the conversion to markdown/text, and clearly differentiates from siblings like 'url.open' by saying 'Page extraction / public URL to markdown' and 'Use after url.open when you need page body, not just risk signals.' This makes its purpose unmistakable.

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?

It provides clear usage context: 'Use after url.open when you need page body, not just risk signals.' This explicitly states when to use it. It doesn't explicitly state when not to use it or name alternatives for similar tasks (e.g., if you need plain text vs markdown is covered by the format parameter), but the guidance is strong enough. No explicit exclusions are given, which is why it's not a 5.

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