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

With no annotations, the description carries the behavioral disclosure burden. It does convey the key behavior: returning language breakdown by bytes. It does not mention error handling, authentication, or behavior when q is empty, but the read-only nature is strongly implied.

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 one short, front-loaded sentence with no wasted words. 'Repo Languages:' is slightly redundant with the title, but the rest is efficient and to the point.

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 lookup with an output schema, this is mostly adequate. The main gaps are the lack of an explicit parameter mapping and unspecified behavior when q is empty, but the core purpose is conveyed.

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?

The schema provides only a q string with no description and 0% coverage, so the description must compensate. 'owner/repo' gives a useful format hint for q, but it does not explicitly state that q should be 'owner/repo' or explain the default empty string behavior.

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 clearly identifies the resource: a repository's language byte-breakdown for an owner/repo pair. It is understandable and distinct from vague names, though it does not use an explicit verb or name a sibling to differentiate from.

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 'Language byte-breakdown for owner/repo' implies this tool is for retrieving a repository's language distribution. However, it provides no explicit when-to-use guidance, exclusions, or alternatives among the many GitHub-related sibling tools.

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