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

Annotations already establish read-only safety, and the description goes beyond them by disclosing the not-found behavior ('Returns null if not found') and the exact response shape contract. Repeating 'Read-only' is redundant but the null semantics are genuinely additive.

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?

One sentence, front-loaded with verb+resource, with the null behavior appended. The parenthetical contract pointer and payload enumeration add slight density but no filler sentences.

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 single-item getter with a full output schema, annotations, and 100% param coverage, the description supplies the essential missing bits (accepted key forms, not-found behavior). It omits any routing hint to search_answers/list_answers, which is the one remaining gap.

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 description coverage is 100% and the single 'id' parameter is already documented as accepting 'stable id or slug'. The description's 'by id or slug' restates the schema rather than adding format, example, or validation detail, so 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?

States a specific verb (Get) and resource (one Answer/contract v0) and enumerates the payload (question, grounded answer, citations). It doesn't explicitly name or contrast with siblings like search_answers or list_answers, though the word 'one' plus the id/slug qualifier implies single-item lookup.

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 'by id or slug' qualifier and 'Returns null if not found' tell the agent what inputs are valid, but there is no explicit when-to-use or when-not-to-use versus the sibling search/list tools. Usage must be inferred from the name.

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