List literature sources

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

Annotations already declare readOnlyHint, so the read-only nature is covered. The description adds useful context beyond that: the exact count (seven), inclusion of credential environment variables, and provider limitations. It doesn't describe output structure, but for a simple read-only tool this is sufficient credit.

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, compact sentence that clearly enumerates the three items the tool lists. No wasted words or redundancy.

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 (no parameters, no output schema, read-only), the description is complete: it tells exactly what will be listed (seven sources, credential env vars, provider limitations). An agent can invoke and interpret the result without further context.

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, so schema coverage is trivially 100%. With no parameters, the description doesn't need to explain parameter meanings; baseline is 4.

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 clearly states a specific action ('List') and resource ('the seven supported literature sources'), and goes further by mentioning credential environment variables and provider limitations. This distinguishes it from sibling tools that search or fetch fulltext.

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 implies usage (e.g., to see available sources before searching) but does not explicitly state when to use this versus siblings. It mentions credential env vars and limitations, which hints at configuration setup, but no explicit when-to-use or when-not-to-use guidance is given.

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