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

Beyond the readOnly/openWorld annotations, the description discloses that auth-gated fields return locked and that a case URL is included for the full record — real behavioral context an agent can't get from annotations. It stops short of describing missing-case or error behavior.

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?

Two sentences, front-loaded with what the record contains, then the access caveat. Little waste; the parenthetical timeline stages are dense but purposeful.

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 read-only single-record tool with no output schema, the description covers return content (timeline, score, citation) and the locked-field caveat. Only edge cases like unknown slugs are unaddressed.

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% and the single slug parameter is fully documented in-schema. The description only reinforces provenance ('from search_cases') without adding format or resolution details, 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?

The description states a specific verb+resource ('One case') and enumerates what comes back: dated spread timeline stages, Spread Score, and citation. It's clearly a single-record read, distinct from search_cases, though it doesn't name the sibling explicitly.

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?

Usage is implied rather than stated: you fetch one case, and the slug must come from search_cases, which gives an implicit routing hint. There's no explicit when-to-use versus list_mechanics or search_cases, and no stated preconditions.

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