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

Annotations cover the safety profile (readOnly, idempotent, non-destructive, closed-world), and the description adds a non-obvious semantic caveat that structured data cannot express: every well-formed jobId resolves as completed, so a result is not evidence the key was created. That is exactly the kind of behavioral warning that prevents an agent from drawing a false conclusion.

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, zero waste. The purpose is front-loaded and the validity caveat follows immediately after, in the order an agent needs it.

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 shape needn't be restated, and the description instead spends its space on the interpretive caveat that matters most. Nothing needed to call or correctly interpret this single-parameter read tool is missing.

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% and the schema already documents jobId as 'returned by create_sandbox_job', including the format pattern. The description's mention of the jobId origin is essentially redundant, 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?

States a specific verb (read) plus the exact resource (status and synthetic result of a sandbox job), and explicitly ties it to the sibling that produces the jobId. An agent can distinguish it from create_sandbox_job without opening either schema.

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?

Names the prerequisite and originating sibling ('a sandbox job created with create_sandbox_job'), giving clear context for when this tool applies. It stops short of stating exclusions or alternative lookup paths, so it is not a full when/when-not statement.

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