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

Annotations already indicate read-only and idempotent behavior. The description adds useful context: the tool returns only public sources and is used to support the public question page. This clarifies the scope and purpose beyond the annotations. No contradictions.

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 consists of two concise sentences. The first states the purpose, the second clarifies input and output. No unnecessary words or repetition. Every sentence adds value.

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?

Given the presence of an output schema, the description adequately covers the tool's behavior: input format, output content, and read-only nature. Annotations cover safety. No additional details are needed for an agent to use this tool correctly.

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?

Even though schema coverage is 0%, the description fully explains the sole parameter slug_or_id: it accepts a question slug or ULID and is required. This adds critical semantic meaning not present in the schema definition, fully compensating for the lack of schema description.

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 returns public Source entities cited by one SkinKnowledgeBase Question. It specifies the input (slug_or_id accepting slug or ULID) and output (source records and canonical URLs). This distinguishes it from sibling tools like search_entities or get_question_bundle, which serve different purposes.

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 explicitly states the required input and what the tool returns, making its usage clear. However, it does not provide guidance on when not to use this tool or mention alternatives among siblings like get_question_bundle, which might also return sources. This lack of exclusion criteria prevents a perfect score.

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