star_repo

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

With no annotations provided, the description carries the full transparency burden. It discloses the side effect (starring adds to the list), the success return value ({ starred: true }), and error conditions (repo not found or insufficient token scope). This is solid but does not mention idempotency or behavior for already-starred repos.

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 two informative sentences plus a docs link. It is front-loaded with the primary action, each sentence provides distinct value (action, effect, return/errors), and there is no redundancy or filler.

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 2-parameter mutation tool with no output schema, the description fully covers the purpose, side effects, return value, failure modes, and related list capability. It is complete and self-sufficient, even linking to external documentation for further details.

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% with both owner and repo clearly described. The tool description does not add any further parameter-level semantics beyond what the schema already provides, so the baseline of 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?

The description opens with a specific verb and resource: 'Star a repository on behalf of the authenticated user.' It clearly states the effect (adding to the starred list) and distinguishes from sibling tools like unstar_repo and check_repo_starred by explicitly naming list_starred_repos as the visibility mechanism.

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 clear context: it acts on behalf of the authenticated user and adds to their starred list, visible via list_starred_repos. However, it does not explicitly contrast with alternatives (e.g., 'use unstar_repo to remove a star') or mention when not to use it, so it falls short of a full 5.

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