bookshelf_get_diskspace

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

The readOnlyHint annotation already covers the read-only behavior. The description adds no extra behavioral context, such as what 'diskspace' refers to (e.g., total space, free space) or any limitations. It is essentially a restatement of the tool's purpose, not additional transparency.

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 with no wasted words. It is front-loaded and clear, though slightly under-specified. For a zero-parameter tool, this level of brevity is acceptable.

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 simple read-only tool with an output schema, the description is minimal but leaves ambiguity about what 'diskspace' means and what the return structure represents. It lacks usage guidance and contextual details, making it incomplete for an agent to fully understand the tool's behavior.

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 has zero parameters, and the schema coverage is 100% (vacuously). The description need not explain parameter semantics, and the baseline of 4 applies due to no params.

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 'List diskspace.' clearly states a specific verb and resource. It is distinguishable from sibling tools like list_filesystem, though it does not explicitly differentiate itself. The purpose is unambiguous despite being terse.

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 provides no guidance on when to use this tool relative to alternatives such as list_filesystem. There is no mention of use cases, exclusions, or context, leaving the agent to infer based solely on the tool name.

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