why

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

With no annotations, the description carries the full burden and does so excellently. It discloses a critical behavioral nuance: the QUANT verdict is oracle-certified while the narrative is interpretive and never a fact. It also clearly states the return JSON structure, giving the agent a complete behavioral model.

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 well-structured with an opening purpose, a critical caveat, and Args/Returns sections. Every sentence adds value, and the formatting makes it easy to scan. It is appropriately sized for the tool's complexity.

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?

Even though an output schema exists, the description provides a comprehensive overview: input format, return fields, and the interpretive boundary. For a single-parameter tool with domain-specific nuance, this is more than complete.

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 has zero description coverage, but the description fully compensates by explaining claim_card_id's source (query_executable) and exact format ({spec_id}:{claim}). This adds meaning far beyond the bare parameter name and type.

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: 'Grounding for one executable-substrate claim-card' and 'Use it to inspect (or cite) a specific sim-verdicted claim.' This is a specific verb+resource combination that distinguishes it from siblings like query_executable (which likely lists claims) and get_evidence (which may retrieve broader evidence).

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?

It provides clear usage context: use for a specific claim-card id when you need to inspect or cite, and explicitly says the id comes from query_executable with format {spec_id}:{claim}. However, it does not explicitly state when not to use it or mention 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.