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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds a genuinely useful prerequisite ('Needs a NativeExpress key'), which the agent would otherwise discover only by failing. It does not say what happens with an unknown or stale slug, which is the main operational risk for a keyed lookup.

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 covering what is returned, what it is good for, the auth prerequisite and the call ordering, with no filler. The prerequisite and routing cue are front-loaded rather than 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?

For a single-parameter read-only lookup with no output schema, the description covers return content ('full text... with what to check'), auth, and sequencing. The only meaningful gap is failure behavior for an invalid slug, which no structured field covers.

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% and the slug property already documents 'The slug from list_build_prompts.' The description restates that provenance but adds no format or validation guidance beyond the schema, 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 and resource ('The full text of one prompt from the NativeExpress library') and adds the outcome shape ('ready to paste, with what to check in the result'). It is clearly distinguishable from the sibling list_build_prompts, which returns slugs rather than full text.

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?

Explicitly routes the agent: 'Use this after list_build_prompts has given you a slug,' naming both the prerequisite tool and the ordering. There is little ambiguity about when this tool applies versus its alternatives.

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