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

Annotations already mark this as readOnlyHint and idempotentHint, so the safety profile is clear. The description adds useful behavioral context: source HTML is only included for apps the caller owns, and the read scope covers both app info and build status. There is no contradiction with annotations, though it doesn't say what happens for non-owned apps.

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?

The description is a single front-loaded sentence with no filler. It communicates the action, resource, addressing mechanism, and a key scope condition efficiently.

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 one-parameter, read-only tool with full schema coverage and readOnly/idempotent annotations, this description is nearly complete for correct invocation. It could clarify the exact return payload or behavior when source HTML is unavailable, but nothing critical is missing.

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%, so the slug parameter is already well documented with an example. The description's mention of 'by slug' reinforces the addressing mode but adds little beyond the schema. 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?

The description states a clear verb and resource ('Read an app or build status by slug') and adds a meaningful scope qualifier ('including source HTML for apps you own'). It does not explicitly distinguish itself from the sibling apps_buildstatus, which may overlap on the 'build status' portion, so it misses the top score for sibling differentiation.

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 description gives no explicit when-to-use guidance or alternatives. Given sibling tools like apps_buildstatus and apps_search, an agent is not told when to prefer this tool over those. The phrase 'for apps you own' is a constraint on returned data, not a routing rule.

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