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

Annotations declare destructiveHint=true, yet the description asserts 'Additive.' MCP defines destructiveHint=false as the additive case, so these directly conflict. A caller deciding whether this is safe gets contradictory signals with no resolution.

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, front-loaded sentences with the essential behavior first and the endpoint last. However, the one-word fragment 'Additive.' does not earn its place since it is the source of the annotation conflict.

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 one-parameter tool with no output schema the description covers purpose, lifetime consequence, and the API mapping. It does not say what the call returns, which is a minor gap given no output schema exists.

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 100% and the single 'uuid' parameter is documented in the schema as 'File UUID to store.', so the description adds nothing beyond it. Baseline 3 applies for a well-covered schema.

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+resource ('Marks a file as permanently stored') and immediately explains the consequence of not doing so (unstored files deleted after 24h), which cleanly separates it from siblings like delete_file and get_file. Even names the underlying REST endpoint.

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 24h deletion note implies when this tool matters (whenever a file must outlive the temporary window), but there is no explicit when-to-use/when-not guidance and no named alternative. Usage must be inferred from the consequence sentence.

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