pmc_search

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

With no annotations provided, the description carries the full burden of disclosing behavior. It states that the tool 'Searches 7M+ full-text articles in PubMed Central' and emphasizes the full-text nature, which is useful. But it does not disclose potential side effects, rate limits, pagination behavior, or whether results are restricted to open access—information that could matter to an agent. It does make the core behavior clear, so it is not a 2.

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 long, with the main action front-loaded: 'Search PMC for full-text articles.' The second sentence provides a crucial clarifying contrast with PubMed. There is zero wasted wording, making it exceptionally concise and well-structured.

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 search tool, the description is complete enough: it identifies the resource, distinguishes from PubMed, and the output schema covers return values. It does not elaborate on result formatting or special behaviors, but the output schema and parameter schema fill those gaps. The only minor omission is lack of any mention of access limitations beyond full-text availability, but this is not critical. Overall, it is complete for the tool's complexity.

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 input schema has 100% coverage of all five parameters, each with a description, so the baseline is 3. The description does not add any parameter-level meaning; it only provides high-level context about the search scope. Since schema already documents parameters fully, the description adds no additional semantic value beyond that baseline.

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 the tool's function: 'Search PMC for full-text articles.' It uses a specific verb and resource, and explicitly distinguishes itself from PubMed: 'Unlike PubMed (abstracts only), PMC searches the complete article text.' This effectively differentiates the tool from the sibling 'pubmed_search' and makes its purpose unambiguous.

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 clear context for when to use the tool: when full-text article search is needed. It names PubMed as an alternative and contrasts them ('Unlike PubMed (abstracts only)...'), giving explicit guidance about choosing PMC over PubMed. However, it does not mention when not to use the tool or discuss other sibling alternatives, so it falls short of a 5.

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