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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered structurally. The description adds genuinely useful context beyond that: it will not create a second attachment, generate media, or spend credits, which is exactly the reassurance an agent needs before re-invoking a confirmation endpoint.

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 filler, front-loaded with the return value and side-effect guarantees. Every clause carries information an agent can act on.

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?

The output schema handles return-value shape, so the description only needs the tool's role and side effects, both of which are covered. Minor gap: no mention of failure modes such as an expired or already-consumed token, though the idempotent annotation mitigates that concern.

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 token's origin is already documented in the schema. The description adds ownership and exactness semantics ('the exact owned uploadToken'), clarifying that the token must belong to the caller — a meaningful constraint beyond the schema's type/length validation.

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: returns pending/accepted attachment status and assetId for a given uploadToken, and reconciles the existing upload. An agent can distinguish this from the URL-generating sibling (studio_media_upload_url) without opening the schema, though no sibling is named explicitly.

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 workflow position is implied (this is the confirmation step that follows obtaining an uploadToken), and the token parameter points back to studio_media_upload_url. However, it never states when to call it versus alternatives, nor what to do on a pending vs. accepted result, leaving sequencing to inference.

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