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

With no annotations, the description carries the full burden and does well: it discloses the return shape (download link + file_name), tells the agent to hand the link to the user, and warns that include_scene adds a few hundred KB. It omits operational traits like latency/cost of rendering and whether the page is fetched live, which keeps it short of a 5.

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?

Purpose is front-loaded in the first clause and the rest of the text is return-value detail, all of it relevant. The single long sentence with stacked parentheticals is dense but contains no filler.

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, the description must explain returns and does: link, file_name, optional scene, plus where the file opens. Given only one required parameter and a simple schema, the remaining gaps (rendering cost, whether the page must be crawlable) are minor.

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%, so both parameters are already documented, and the description largely restates them. The only added value is the quantitative size hint ('a few hundred KB') for include_scene versus the schema's vague 'large', which is marginal.

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 verb and resource ('Draw a page's anatomy as an Excalidraw diagram') and enumerates the diagram's contents (regions, ranked data-access routes, proof rows, best route). The output format implicitly separates it from xray_page, but no sibling is named, so differentiation relies on inference.

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 the visual/diagram variant of page analysis. There is no explicit 'use this when you want a shareable visual rather than a text report' statement, no exclusion, and no mention of when xray_page would be the better choice.

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