thumbmoves_backend_info

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety and locality are covered. The only behavioral hint the description adds is "cache-only", and it does not say whether this is a pure introspection call, what environment it must run in, or what happens if the native platform is unavailable.

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?

One short, front-loaded sentence with no filler or repetition. It is efficient, though its brevity comes at the cost of the clarifications noted elsewhere.

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 values need not be described. Still, for a read-only introspection tool surrounded by many sibling tools, the description should at minimum say what the contract covers and when to reach for it; the single abstract sentence does not give the agent enough to decide confidently.

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?

The tool effectively takes a single empty wrapper object with no fields, so there is little parameter meaning to convey. The description does not mention the arguments envelope at all, but the schema makes its emptiness explicit, so the gap is minor.

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?

"Inspect the native platform's cache-only thumbnail backend contract" names a verb (inspect) and a resource (thumbnail backend contract), so the topic is identifiable. However, "contract" and "cache-only" are jargon that leaves it unclear whether the tool returns diagnostics, version info, supported formats, or capabilities, and it never contrasts itself with the sibling thumbmoves_cached_thumbnail.

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 guidance on when to call this versus thumbmoves_cached_thumbnail or any other thumbmoves tool, and no prerequisites or exclusions are stated. The agent must infer call conditions purely from the phrase "backend contract".

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