Describe One Operation

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

Annotations already establish readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description still adds real behavior beyond that: no fuzzy matching, and an unknown key yields a CONFIG_ERROR naming the nearest catalog keys. It is only mildly incomplete on return shape, which the output schema covers.

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?

Front-loads what the tool returns and then the routing, with no filler sentence. The long em-dash aside about key format is dense but each clause carries distinct information, so it is appropriately sized rather than wasteful.

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 values, and it covers the remaining gaps: when to call it, key format, and error behavior. Nothing an agent needs to invoke it correctly is missing.

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%, so the baseline is 3, but the description adds semantics the schema does not carry: the CONFIG_ERROR failure mode for unknown keys and the explicit 'never a tool name' prohibition. It does partly repeat the schema's own property description, keeping it short of a 5.

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 (Return) and a precisely enumerated resource (input schema, effect, flags, dry-run support, error vocabulary, related operations, preferredWhen) scoped to ONE operation, and explicitly contrasts itself with hudu_list_operations and hudu_read/write/delete. An agent can identify it without opening any schema.

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?

Gives explicit sequencing: 'Use it after hudu_list_operations named the operation and before hudu_read/hudu_write/hudu_delete.' Both the predecessor and the successors are named, which is exactly the routing an agent needs.

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