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

Annotations already declare read-only, idempotent, closed-world and non-destructive, so the safety profile is covered. The description adds real behavioral value beyond that: it discloses the return payload (bounded preview, original download URL, metadata, expiration), notes that PDFs and extracted content return links instead of images, and explains multi-output selection.

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 dense sentences with the primary resource and return shape front-loaded, followed by the two exceptional cases (PDFs, multi-output). No filler; every clause carries 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?

With no output schema, the description does a fair job of describing the return payload, but it omits what happens when the result is incomplete or expired (error vs. pending), leaves 'id' undefined, and gives no guidance on the relationship to get_screenshot.

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 0%, so the description carries the burden. It does explain outputId ('selects a multi-output result'), but the required 'id' parameter is never described — the agent must infer it identifies the screenshot, and the 10-character pattern is only in the schema.

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 and resource ('Retrieve a completed screenshot') and enumerates what comes back: bounded image preview, download URL, metadata, expiration. It does not, however, explicitly distinguish itself from the sibling get_screenshot, whose role overlaps closely enough that the agent must infer the difference.

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: the word 'completed' hints this is the post-capture retrieval step, but there is no statement of when to use this versus get_screenshot, or what to do if the result is not yet ready. No alternatives or exclusions are named.

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