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

Annotations already declare readOnly, openWorld, idempotent, and non-destructive, so safety is covered. The description adds genuinely useful semantics beyond that: results are live and unchecked, and carry a separate unchecked label, which tells the agent how to treat the output. It stops short of noting latency, rate limits, or that results may be incomplete relative to the indexed corpus.

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?

Three short sentences, front-loaded with the core action, followed by routing guidance and then provenance semantics. Every sentence carries distinct information with no padding.

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?

An output schema exists, so return values need not be explained. For a read-only, open-world search tool the description supplies purpose, routing, and result-provenance context — everything an agent needs to select and invoke it correctly.

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?

Schema coverage is 100%, so q, limit, cursor, and peptide are all documented in the schema, including the cursor reuse instruction. The description adds no parameter-level detail beyond that, so the baseline 3 applies.

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?

States a specific verb and resource ('Return live, unchecked papers') plus the upstream source ('from Europe PMC'), and immediately marks the results as unchecked. This lets an agent distinguish it from search_publications and search_findings without opening either schema.

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?

Gives explicit when-to-use conditions ('gaps in database coverage or an explicit live literature search') and names two alternatives with the condition that selects each (stored papers → search_publications, checked claims → search_findings). Nothing is left to inference.

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