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

Adds real behavioral context beyond the annotations: it is free, makes no Apple calls or paid compute, and crucially discloses the boundary 'Does not prove compilation, signing or TestFlight delivery'. This negative scope is genuinely useful and not present in the structured fields. It does not address why readOnlyHint is false, leaving a minor gap.

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?

Two tight sentences: the core purpose is front-loaded, then the follow-up action and the limitation. Every clause earns its place with no redundancy.

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?

An output schema exists, so return values need no explanation. The description covers purpose, cost profile, boundary conditions, and the follow-up tool, which is sufficient for a one-parameter check. Minor omission is any note on whether it mutates state given readOnlyHint=false.

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?

With a single parameter at 100% schema coverage, the schema already documents project_id fully (including where to find it). The description adds no syntax or format detail beyond that, 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 and resource: a source-readiness check of the latest uploaded snapshot. The scope qualifiers ('free', 'no Apple calls or paid compute') further pin down what kind of check this is, distinguishing it from build/signing 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?

Explicitly routes the agent: 'Run push_project after source changes' names the sibling and the triggering condition. It stops short of stating when NOT to use check_project (e.g. versus build), so it lacks the full alternatives/exclusions treatment that would earn a 5.

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