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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds context about the metric (distinct compounds/agents, modality/outcome breakdown) but does not disclose additional behavioral traits such as data coverage, performance, or rate limits. Since annotations carry the safety burden, this is adequate.

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 no wasted words. It front-loads the core concept immediately and then explains the input format, making it easy to scan and understand.

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?

This is a simple read-only query tool with a single parameter, strong annotations, and an output schema. The description fully covers the purpose and input format, while the output schema handles return values. Nothing critical is missing.

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 schema covers 100% of the single parameter (target) by specifying gene symbol or UniProt accession. The description reinforces this with concrete examples (EGFR, P00533), which is helpful but not essential beyond the schema. Baseline of 3 applies because the schema does the heavy lifting.

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 'graveyard/exhaustion index' that counts distinct compounds/agents tried against a target and failed, broken down by modality and outcome. This is a specific verb+resource with a unique scope that distinguishes it from the many search_* siblings.

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 answers the question 'how picked-over is this target?', giving a clear use case for when to employ this tool. It does not explicitly name alternatives or exclusions, but the context is sufficient to differentiate it from the sibling search tools that focus on specific failure types.

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