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

Annotations already declare readOnlyHint, idempotentHint and non-destructive behavior, so the bar is lower. The description still adds real value beyond those flags: it states the return shape (question, grounded answer, visible citations) and the concrete 'Returns null if not found' behavior, which annotations cannot express.

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?

A single compact sentence front-loads the resource, the lookup key, and the returned contents, then tacks on the read-only and null-return facts. No sentence is wasted and nothing is buried.

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 no output schema, the description takes on the burden of describing returns and does so via the field list plus the null case and a pointer to the Answer contract doc. It is close to complete; the shape reference is a doc name rather than an inline structure, leaving a small gap for an agent that cannot read ANSWERS-PROGRAM.md.

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% with a single self-documented parameter, so the schema already carries the semantics. 'By id or slug' matches the schema's 'stable id or slug' description and adds no format, validation, or ambiguity-resolution detail beyond it; baseline 3 is appropriate.

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') scoped to a single lookup by id or slug, and enumerates the returned fields (question, grounded answer, visible citations). The singular 'one Answer ... by id or slug' distinguishes it from list_answers and search_answers without ambiguity.

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 id-or-slug lookup key implies when this tool is appropriate versus the list/search siblings, but there is no explicit when-to-use or when-not statement. An agent can infer the case, but the description never names search_answers or list_answers as the alternatives.

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