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

Adds substantial context beyond annotations: 1 MB cap, auto-creation of parent directories, persistence across stops/restarts, refusal of truncated base64, and verification via SHA-256 returned in the answer. The annotations already declare destructiveHint/idempotentHint, and the description does not say what happens to an existing file at the same path (overwrite vs. error), which is the one behavioral detail a destructive write tool should cover.

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?

The core action and limits are front-loaded, and each subsequent sentence carries a distinct decision or constraint (size, startup files, large files, path scope). The SHA-256 verification sentence is dense but earns its place; overall the paragraph is longer than ideal but not padded.

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 still tells the agent what comes back (SHA-256 of written bytes) and how to use it. Size limits, persistence, error behavior (truncated base64 refused), and alternatives are all covered, so an agent can invoke this correctly on the first attempt.

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% (only `path` is described), so the description must compensate, and it largely does: it clarifies that `path` refers to the briq's own filesystem, and constrains `contentBase64` (max 1 MB, must be complete, not truncated). The `briq` identifier itself is left to the schema's pattern with no explanation of how to obtain one.

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 ('Upload a file ... into a running briq') and immediately scopes it against the two plausible alternatives: the `files` field of briq_run and briq_exec for larger payloads. An agent can separate this from briq_files_get and briq_run without opening any 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?

Explicit when-not-to-use guidance: startup files belong in briq_run's `files`, oversized content should be fetched inside the briq via briq_exec (git clone/curl), and GitHub code uses a recipe's `checkout`. It also states an operational precondition (a briq whose command fails never gets far enough to upload), which is exactly the routing information an agent needs.

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