redis_hget

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

Since no annotations are provided, the description carries the full burden of behavioral disclosure. It simply states 'Get one field from a hash' and does not disclose what happens if the field or key does not exist (e.g., returns nil), whether the operation is read-only, or any error conditions. The description adds no behavioral context beyond the obvious read action, leaving important aspects ambiguous.

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 extremely concise, using a single sentence, which is positive for front-loading. However, it lacks any structure or elaboration—no prerequisites, no examples, no explicit parameter roles. It is appropriately short but sacrifices clarity and utility in the process, making it borderline under-specified rather than efficiently concise.

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 (2 params, no output schema, no annotations), the description still omits critical context such as return values (nil if field missing), behavior on missing keys, or any error semantics. An agent could call this tool without knowing what to expect, making it incomplete for a reliable invocation.

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 schema has 0% description coverage, and the description provides no additional meaning for the two parameters, key and field. It does not explain that 'key' refers to the hash name and 'field' to the specific field within that hash. The description adds nothing beyond the parameter names already present in the schema, so an agent cannot infer the exact purpose of each parameter from the tool definition alone.

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 states a clear verb ('Get') and specific resource ('one field from a hash'), which tells the agent exactly what it does. It doesn't explicitly differentiate from siblings like redis_hscan (which scans fields) or redis_get (which retrieves whole values), but the phrase 'one field' makes the intent unambiguous enough for a basic read operation.

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?

No guidance is provided on when to use this tool versus alternatives. It doesn't mention that it is for retrieving a single hash field specifically, nor does it note when to prefer redis_hscan (for multiple fields) or redis_get (for non-hash values). The agent is left to infer from the name and description alone, which may cause mis-selection.

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