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

Annotations already declare idempotentHint/readOnlyHint/destructiveHint, but the description adds real behavioral context beyond them: the required grant, the confirm gate, that it stores bytes only (not a durable asset), that it debits no credits, and idempotency discipline ('never substitute ids or repeat blindly'). That is substantive disclosure layered on top of the annotations.

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 action and prerequisites, then parameters, then follow-up workflow. Five dense sentences, all carrying information, though the parameter sentence is long and could be split for readability.

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?

For a 7-parameter mutation with no output schema and low schema coverage, the description supplies auth, idempotency, size/transport choice, and the follow-up workflow. The main omission is the bucket parameter's role and any explicit return-shape note, but the finalize pointer largely covers the outcome.

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 only 29%, so the description must compensate, and it does: it specifies uploadId as a stable UUID, sha256 as the exact file digest, mimeType as supported, and the either/or of base64 bytes vs public https sourceUrl. It omits any mention of the bucket parameter and only implies the confirm flag, leaving a small gap.

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 an image/video/audio file into the Library) plus scope (owner upload namespace). It names sibling tools (soclo_library_finalize, soclo_library_upload_status) so the agent can distinguish this step from the surrounding finalize/status workflow without opening schemas.

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 prerequisites (manage:library grant, confirm: true after owner approval of the exact item) and explicit routing: call finalize for the durable id, call upload_status after interruption. This is when-to-use and when-to-call-which-sibling guidance, not inference.

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