View-source screenshot

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

With no annotations, the description is the only source of behavior, and it does disclose that a PNG file is written to disk and that the file path plus matched lines are returned. It leaves gaps around fetching behavior — 'the way a browser does' is ambiguous about whether JavaScript executes — and says nothing about authentication, redirects, or failure modes.

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 sentences, front-loaded with the core action and ending with the return values. There is no filler and every clause adds information.

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 nine-parameter tool with fully documented schema and no output schema, the description covers the action, the side effect of writing a file, and the return shape. The main remaining gap is the absence of any guidance relative to view_source_find, which matters given they overlap.

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 description coverage is 100%, so every one of the nine parameters, including mode's enum and the match regex prefix, is already documented in structured fields. The description's mention of 'highlight matches' and the returned path adds nothing beyond that, so the baseline 3 applies.

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 gives a specific verb chain and resource: fetch a page's raw HTML, render it view-source style, highlight matches, and save a PNG. That is clearly distinguishable from a generic page screenshot. It does not, however, distinguish itself from the sibling view_source_find.

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: an agent can infer this is for capturing a visual of source with highlights, but there is no explicit when-to-use or when-not guidance. The sibling view_source_find is never mentioned, so the agent has no stated rule for choosing between searching source and screenshotting it.

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