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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds value beyond that by stating the URL is authenticated, noting the credential-helper hint, and enumerating the returned object fields {url, owner, repo, defaultBranch, hint} in the absence of an output schema.

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?

Three short sentences, with the core action stated first, then the safety rationale, then the return shape. No filler or redundant restatement of the tool name.

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 two-parameter read with no output schema, the description supplies the return shape and the casing behavior, which covers what an agent needs to call and consume it. Missing only failure-mode context such as what happens when the repo does not exist or the caller lacks access.

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 coverage is 100%, so the baseline is 3. The description earns an extra point because 'using the repo's stored casing' tells the agent that lookups tolerate casing differences and that the response normalizes to the stored casing, which is meaning the schema does not convey.

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: 'Return the authenticated HTTPS clone URL for a repo', and immediately adds the credential-helper hint. This distinguishes it from the sibling token tools (merjax_get_token, merjax_list_repo_tokens) which return raw credentials rather than a clone URL.

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?

It gives explicit usage guidance: 'Use this instead of embedding tokens in URLs', which tells the agent the condition that selects this tool over credential-based alternatives. It stops short of naming specific sibling tools or excluding cases, so it is clear context without full when/when-not coverage.

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