plate_capture

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

No annotations are provided, so the description carries the full burden. It discloses meaningful behavior: an isolated Chromium browser, return of an actual MCP image plus overflow/image-loading/page-error evidence, and no authenticated sessions. It does not mention failure modes or rate limits, but it covers the most important behavioral traits for this kind of tool.

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?

Three short sentences, front-loaded with the primary action and scope, with each sentence adding a distinct piece of useful information: what it captures, what it returns, and a key limitation. No filler or redundant restatement of the tool name.

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 no annotations, the description should clearly explain return values and parameter semantics. It mentions the return evidence but only vaguely ('overflow, image loading and page error evidence'), and it leaves width/height/wait_ms meaning to the schema. It is adequate for a simple capture tool but has clear gaps.

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 only 20%, and the tool description does not explain url, width, height, or wait_ms. Saying 'Capture a running local website' only loosely implies the url parameter. The schema provides ranges but not semantic meaning, and the description fails to compensate for the low coverage.

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 concrete action ('Capture') and a specific resource ('a running local website') with an isolated Chromium browser, and adds what it returns (MCP image plus evidence). It is clear and unique among the plate_* siblings, though it does not explicitly contrast itself with any sibling tool.

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 clear usage context: use this for a running local website that needs an isolated-browser capture, and it explicitly warns 'No authenticated sessions,' which functions as a when-not constraint. It does not name alternative sibling tools, so it stops short of full routing guidance.

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