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 value (`content` UTF-8 by default vs `content_base64`), the auth/runtime prerequisite, the 5 MB cap, and the context-bloat tradeoff of pulling base64. It doesn't cover failure modes (missing file, dead sandbox) but the core behavior is transparent.

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?

Front-loaded with the core action and size constraint. Slightly repetitive, restating 'max 5 MB' and the get_download_url redirect twice, but the redundancy reinforces the key boundary and wastes little.

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?

No output schema exists, so the description rightly explains the return shape (`content` vs `content_base64`). Combined with size limits, auth requirements, and the sibling alternative, an agent has everything needed to call this correctly.

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 only 33%, so the description must compensate, and it does: it clarifies `path` must be absolute and that `as_text: false` returns `content_base64` while text is the default, plus names sandbox_id and its liveness requirement. This adds real meaning beyond the schema patterns.

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: read a SMALL file from the sandbox into the conversation. It draws an explicit boundary against the get_download_url sibling for large/binary files, so an agent can distinguish them 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?

Gives explicit when-to-use conditions (small files under 5 MB) and when-not (build artifacts, archives, binaries, anything big) with the named alternative (get_download_url). Prerequisite is stated: token + live sandbox_id.

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