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

readOnlyHint=true already tells the agent this is a safe read, so the description need not restate safety. It adds the underlying REST mapping (GET /builds), which is mildly useful for developers, but says nothing about pagination, result limits, or ordering — gaps that matter for a list endpoint.

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, filter scope front-loaded and the REST mapping tucked at the end. Every clause carries information; nothing is padding.

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 zero-required-parameter list tool with no output schema and read-only annotations, the description covers purpose and filterability adequately. The only meaningful omission is pagination/result-size behavior, which is a minor gap rather than a blocking one.

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 all three filters are already documented in the schema. The description only enumerates the same filter dimensions (application, workflow, branch) without adding format, matching behavior, or combination semantics, so 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 (List) and resource (builds) with scope of optional filters, which cleanly separates it from codemagic_get_build (single build) and codemagic_list_applications. It does not explicitly name a sibling, so it stops short of a 5.

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 phrase 'optionally filtered by' implies the tool is for browsing/enumerating builds and that filters are optional, but it gives no explicit when-to-use versus codemagic_get_build or when-not to use it. Usage is inferable but not stated.

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