save_pdf

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

The description usefully discloses that output is written to the output dir, but that write side effect is in direct tension with the readOnlyHint=true annotation. It also says nothing about whether existing files are overwritten or what the returned payload contains.

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?

Two short sentences, zero waste, with the hard precondition (headless only) surfaced immediately alongside the core action.

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?

An output schema exists, so return values need not be explained. Still, for a file-producing tool the description omits overwrite behavior and filename/path handling, which is the main thing an agent must get right.

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?

There is one parameter with 0% schema description coverage; the description never mentions 'filename', its default 'page.pdf', or whether it accepts relative paths versus full paths. The 'output dir' phrase hints at path resolution but does not resolve it.

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 ('save') and resource ('the page as PDF') plus the output location, so an agent knows exactly what the tool produces. It does not name a sibling alternative (screenshot_file, save_html) for disambiguation, keeping it below a 5.

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?

'(headless mode only)' is a genuine precondition that narrows when the tool works, which is better than nothing. However, it gives no guidance on when to prefer this over save_html/screenshot_file, nor what to do in non-headless sessions.

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