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

Annotations already cover read-only, idempotent, and non-destructive behavior. The description adds the meaningful facts that the result is fixed, synthetic, and carries no live-fetch or truth guarantee, which is context beyond the annotation flags. There is no contradiction with annotations.

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 short sentences, each earning its place: the first states the operation, the second states the limitations. The most important scope information is front-loaded.

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 no-argument, read-only fixture tool, the description is sufficient: it names the resource, states the synthetic or fixed nature, and flags non-guarantees. It does not describe the returned fixture's shape, but the absence of an output schema and the intentionally simple scope make that omission minor.

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?

With zero parameters and 100% schema coverage, there is no parameter semantics for the description to add. The empty schema fully documents the input contract, so the baseline score of 4 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 opens with 'Read a fixed synthetic evidence example,' providing a concrete verb and resource. This clearly frames the tool as a read-only fixture accessor, distinct from live-data or validation tools. The title 'citation evidence fixture' reinforces the specific resource.

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 second sentence gives a clear negative usage signal: this is not for live data, payment-dependent content, or assertions of truth. That tells an agent when not to use it, but it does not name a specific sibling alternative such as get_manifest or get_evidence_contract for live or validated evidence.

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