library_summary

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

There are no annotations, so the description carries the full burden of behavioral disclosure. It implies a read-only, informational output about free vs subscription contents, but does not specify the return format, side effects, or any other behavioral nuances. Minimal transparency beyond the surface meaning.

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 a single sentence with no filler or redundant phrasing. It front-loads the core content and is appropriately sized for a zero-parameter informational tool.

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 parameterless tool with no output schema, the description gives a general sense of the content but omits details an agent might need, such as the format of the summary (text, list, etc.) or how detailed the information is. It is adequate for a very simple informational tool but not fully complete.

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?

With zero parameters, the baseline is 4. The description adds contextual meaning by clarifying what the tool's content covers (free list and subscription additions), which is useful even though there are no parameters to document.

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 conveys the subject matter—what the free list contains and what a subscription adds—but lacks a direct verb or explicit statement of the operation (e.g., 'Returns a summary...'). It is not tautological and hints at the tool's informational purpose, but it is vague about the exact action.

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 given on when to use this tool versus its siblings, nor any context, prerequisites, or exclusions. The description is a standalone phrase with no indication of the scenario in which this tool is appropriate.

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