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

Annotations already declare readOnlyHint and closed-world, so safety is covered. The description adds genuinely useful field-level context, notably that DSN is null for a read key, which is behavioral info beyond the annotations, though it omits error/not-found behavior.

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 that lists the returned fields with zero wasted words, matching the low-complexity single-param tool.

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 simple single-resource read with full schema coverage and readOnly annotations, the description is essentially complete; the only minor gap is not stating behavior when the app is not found or lacks access.

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 single appId param is fully documented including that it accepts id or slug from list_apps. The description adds no additional parameter meaning, so the 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+resource ('One app') and enumerates exactly what it returns (name, slug, platform, page, DSN, first/last event timestamps), clearly distinguishing it from list_apps and the other get_* siblings.

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 implied: it fetches a single app by id, and the schema note 'from list_apps' hints at the list-then-get flow. However, there is no explicit when-to-use-vs-list_apps guidance or exclusions.

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