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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and a closed world, so the safety profile is covered. The description adds genuine behavioral context beyond that: it distinguishes the persisted choice from what uploads currently resolve to, and names the possible resolved targets (workspace default vs. Fillo's short-lived transit staging).

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 compact sentence with the key distinction (stored vs. resolved) front-loaded and no filler. It could be marginally clearer about the read action, but nothing is wasted.

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 an output schema present, the description need not enumerate return fields, and it still characterizes the two-part answer (stored choice and effective resolution). For a one-parameter read tool with full annotation coverage, this is essentially complete.

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 single 'form' parameter is fully documented in the schema (id, slug, or push handle), so the schema already does the work. The description adds no parameter-level syntax or format detail, which makes the baseline 3 appropriate.

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?

The description names a specific resource (a form's file-upload destination) and what is returned (the stored choice plus the current resolved target). The action verb is only implied via the title, but the resource is unambiguous and clearly distinct from fillo_set_storage.

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?

There is no explicit when-to-use guidance and no mention of the obvious complement, fillo_set_storage, or of fillo_get_settings. The read-only nature of the tool is inferable from the phrasing, but the agent is left to infer the routing on its own.

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