Full report

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

The description goes far beyond the annotations by revealing async behavior, polling cadence, the server-side default reports folder, the requirement that directories already exist, the fact that nothing is overwritten, and the 150KB/font-embedding tradeoff. This is exactly the behavioral context an agent needs to act safely and correctly.

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 long but every sentence carries operational weight: purpose, output, file handling, directory rules, polling, and performance. It is front-loaded with the core purpose and uses capitalized imperatives like "USE THE HTML" and "ASK THE USER WHERE THEY WANT IT FIRST" to surface critical action items.

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 no output schema and a complex async, file-writing workflow, this description covers everything an agent needs: return formats, job-ID polling, file-saving behavior, folder constraints, and when to avoid saving. No critical operational detail appears to be 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?

Although schema coverage is 100%, the description adds substantial meaning beyond the schema: directory must be user-chosen and existing, html=false is for conversation-only answers, saving to a file is preferred because the HTML loses fonts in conversation, and paths must never be invented. This clarifies how to produce valid parameter values in real use.

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 opens with a clear definition of the tool: "The whole picture for a page in one call" and lists exactly what it returns — scores, real-user data, and failures ranked by fix value. It also distinguishes itself from siblings by being the aggregate report rather than a single-purpose check like check_pagespeed or field_data.

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?

The description gives strong operational context: it is slow, returns a job ID, requires polling via check_status, and should be used when the user wants a complete picture. It also gives explicit instructions about asking the user for a save location beforehand and setting html=false when only a conversational answer is needed. It does not explicitly name sibling tools as alternatives for narrower cases, so it stops short of a full 5.

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