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

The annotations already establish readOnlyHint=true and destructiveHint=false. The description adds useful behavioral context: 'Keyless / free tier' reveals authentication requirements, and 'Cache LRU 12h' discloses caching behavior. No contradiction with annotations.

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 two sentences with a bullet-like structure, front-loading the purpose and then listing sources and modes. Every phrase adds value (sources, modes, keyless, cache) without 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?

The description covers purpose, sources, modes, and operational constraints (keyless, cache) for a fairly complex 8-parameter tool. Since an output schema exists, return values needn't be described. It doesn't mention async behavior, but the schema documents that.

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?

All 8 parameters have schema descriptions (100% coverage), so the schema does the heavy lifting. The description repeats the mode list but adds no new parameter-specific information beyond the schema. Baseline 3 is appropriate.

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 defines the tool as a multi-source bibliographic search on scientific literature, listing specific sources (OpenAlex, Semantic Scholar, arXiv, PubMed, CrossRef) and modes. This distinguishes it from general web search tools like web_search_multilang and QA tools like research_paper_qa.

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 mentions the main use case (scientific literature search) and lists four modes (search, meta_analysis, citation_network, expert_finder) that indicate different analytical uses. It doesn't explicitly state alternatives or exclusions, but the context is clear enough for an agent to decide when to use it.

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