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

Annotations already declare non-readOnly, non-destructive, non-idempotent. Beyond that, the description discloses the actual verification behavior (checking declared size, type and checksum) and the post-condition that the upload becomes bindable — real behavioral value. It omits failure handling, i.e. what happens if verification fails, which keeps it out of 5 territory.

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?

A single front-loaded sentence with no filler, leading with the verb. Slightly dense phrasing ('return the upload ready to bind to a generation') costs it the top mark.

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 format is covered elsewhere, and annotations cover the safety profile. Still, for a non-idempotent state transition the description says nothing about retry/failure behavior or what the caller should do if verification fails, leaving a meaningful gap.

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 description coverage is 0% across four parameters, and the description compensates poorly: it never mentions upload_id, width, height, or checksum_sha256 by name, and it is unclear why a completion step takes width/height (presumably dimension overrides). The word 'checksum' is the only indirect tie to any parameter.

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 set (verify, return) on a specific resource (an upload), and the finalizing framing ('ready to bind to a generation') distinguishes it from create_upload/get_upload/update_upload. It stops short of naming or contrasting with those siblings explicitly, so it lands at 4 rather than 5.

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?

The phrase 'return the upload ready to bind to a generation' implies this is the terminal step after bytes are sent, which is usable context. However there is no explicit when-to-use/when-not guidance and no reference to create_upload (starting an upload) or get_upload (inspecting one), so usage is only inferred.

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