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

Annotations already declare readOnlyHint and openWorldHint, so safety is covered. The description usefully discloses what the response contains (markdown instructions plus associated friction records), but says nothing about behavior for an unknown slug or how the locale English fallback manifests.

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 front-loaded sentence with no filler, and the payload contents are listed before the auxiliary friction-record clause. Slightly awkward phrasing ('the pattern... plus the friction records it protects against') but efficient.

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 does the necessary work of stating the return format (markdown) and the included friction records. For a read-only two-parameter lookup, the remaining gaps (invalid-slug behavior, response shape details) are minor.

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%, documenting both slug and locale (including the German fallback), so baseline 3 applies. The description adds no meaning beyond the schema for either parameter.

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 the resource (the complete prevention pattern for a slug) and enumerates the payload: the pattern, when to use it, step-by-step markdown instructions, and the friction records it protects against. That distinguishes it from list_patterns and get_friction_record by content, though it never names a sibling explicitly.

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?

Usage is only implied: 'for a slug' plus the schema note that slugs come from list_patterns suggests this is the detail-fetch after listing. There is no explicit when-to-use or when-not-to-use statement, and no routing away from lookup_error or get_friction_record.

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