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

The readOnlyHint annotation already establishes this as a safe read. The description adds modest value by stating the response includes build status and by disclosing the underlying REST call (GET /builds/{id}), but says nothing about what happens on a missing/invalid build id or about any error 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?

Two short sentences, both front-loaded with the essential information: what it returns and the endpoint backing it. Nothing is padded.

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?

There is no output schema, so the description carries some burden for describing the return value, and it only mentions status. For a simple single-entity fetch this is adequate but not fully informative about the build object's contents.

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% for the single buildId parameter, so the schema already carries the semantics. The description confirms the id is the lookup key but adds no format or source 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 (get a single build by id) and clarifies the returned content includes status. It implicitly differentiates from the list-oriented sibling codemagic_list_builds, though it never names the alternative.

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?

No when-to-use guidance, no prerequisites, and no comparison to siblings such as codemagic_list_builds or codemagic_get_application. The 'by id' phrasing hints at the required input but gives the agent no routing logic.

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