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

Annotations already establish that this is a read-only, idempotent, non-destructive, closed-world operation. The description adds useful behavioral context beyond that: the tool returns exactly seven cited retrospective files, not an aggregate cohort, and no European recall percentage should be expected.

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 definition is short and front-loaded with the core action and scope. The second sentence usefully rules out cohort-style aggregation, though the 'unrecalibrated Indian lenses' phrasing adds ambiguity rather than cleanly earning its place.

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 one-parameter read tool with rich annotations and no output schema, the description provides enough context to select and call it: scope, cardinality, citation status, and the absence of an aggregate percentage. Greater detail about what a case file contains or what 'unrecalibrated Indian lenses' means would improve completeness.

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 single slug parameter is fully documented in the schema, including the example and the instruction to omit it for all seven files. The description does not add further meaning about slug syntax or behavior, so the schema carries the parameter semantics.

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: reading seven cited European retrospective case files. It also distinguishes the resource from a cohort by saying these are named case studies with no European recall percentage. The phrase 'unrecalibrated Indian lenses' is opaque, but the core resource is still identifiable.

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 when the tool is appropriate by contrasting named case studies with a cohort and warning that there is no aggregate percentage to quote. However, it does not name alternative sibling tools or explicitly state when to choose evidence_india, evidence_us, or another evidence tool instead.

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