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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint false, so the safety profile is clear. The description adds useful context by stating the citation is 'canonical, reproducible' and listing its fields, aligning with the idempotency hint and revealing what the output will contain.

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 the core action in the first sentence and the purpose/cross-reference in the second. It is front-loaded, free of filler, and every phrase contributes to understanding.

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?

With one parameter, complete annotations, and no output schema, the description sufficiently covers what the tool does and what the citation includes (title, domain, source, content_hash, kb_snapshot). It could go deeper into return format, but for this simple tool it is adequately 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 input schema fully documents the single 'id' parameter with description, minLength, and maxLength. The tool description only repeats that the operation is 'by id' without adding further constraints or formatting details, which matches the baseline of 3 for high schema coverage.

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 starts with a specific verb and resource: 'Get a canonical, reproducible citation for a knowledge entry by id.' It also enumerates the citation's components (title, domain, source, content_hash, kb_snapshot), which distinguishes it from sibling tools like coldstate_verify or coldstate_fetch.

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, 'Cite a fact so it can be re-verified later with coldstate_verify,' provides a clear use case and explicitly ties the tool to a sibling for verification. While it doesn't list when not to use it, the context strongly implies the appropriate scenario.

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