file_storage

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

With no annotations provided, the description must carry the full behavioral burden. It discloses three actions (get, set, delete) and notes persistence across sessions, but omits details like error behavior (e.g., missing key), concurrency semantics, or data size limits. The mention of 'KV-backed' helps but is insufficient for a mutation-focused tool.

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?

The description is two sentences plus a parameter list. The first sentence immediately conveys the purpose. The parameter list is clearly separated and uses plain language. Every sentence adds value with no fluff, making it highly efficient.

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?

Given the tool's simplicity (3 parameters, no nested objects) and the existence of an output schema, the description covers the essential aspects: purpose, parameters, and actions. It lacks examples or edge-case behavior but is complete enough for typical usage. Sibling tools are unrelated, so no comparative context is needed.

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 0%, so the description must compensate. It adds meaning by explaining 'key' as 'Unique file key', 'value' as 'file content' for set actions, and listing action options (get, set, delete) with defaults. This goes beyond the plain schema, making parameter usage clearer, though it could explicitly enumerate action values.

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?

Description clearly states 'Read or write persistent file storage across sessions (KV-backed)'. This provides a specific verb-resource pair and distinguishes it from sibling tools, most of which are unrelated (e.g., calculators, text analysis). It establishes the tool's core functionality succinctly.

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 explains what the tool does but gives no guidance on when to use it versus alternatives. It mentions 'KV-backed' but doesn't contrast with other storage tools or suggest scenarios where this tool is appropriate or inappropriate. Lack of exclusion criteria or sibling references limits its usefulness.

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