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

Annotations already declare the safety profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false), so the description's marginal job is the two-step protocol, which it does state. It adds that the URL is user-bound and the params only preserve metadata, but omits key behavioral facts for a 'temporary' credential: URL lifetime, reusability of the presigned PUT, and whether metadata is reflected into objectKey.

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?

Three short sentences, each doing distinct work: what is created, what the optional params do, and how to complete the flow. The core action is front-loaded with zero filler.

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 structure needn't be explained, yet the description helpfully names uploadUrl and objectKey to tie the response to the workflow. For a two-optional-parameter tool the coverage is nearly complete; only the expiry semantics of the 'temporary' URL are missing.

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 0%, so the description must carry the parameters, and it does: both are marked optional and their effect is explained as metadata preservation rather than path control. That is meaningful added semantics, though it doesn't show format expectations or examples.

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 — 'Create a presigned PUT URL' — plus the scope qualifier 'bound to the current user'. That is unambiguous and unlike any sibling, though it never addresses near-neighbors such as createLedgerFiles, so an agent could still wonder when a direct upload path applies.

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 description gives real operational context: upload bytes to uploadUrl, then use objectKey in an ingestion workflow. That clarifies the intended place in a pipeline. It stops short of exclusions (e.g., when to prefer a different file-creation path) or expiry/when-not-to-use guidance.

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