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

Goes well beyond the destructiveHint annotation: it discloses optimistic concurrency semantics via the blob sha, the required auth scope, that branch protection, rulesets and secret scanning all apply, and that CI and webhooks fire exactly as on a push. Those downstream side effects are precisely what an agent needs before performing an irreversible write.

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?

Four short sentences, action and resource front-loaded, then prerequisites, then side effects, then the REST analogue. No filler and nothing repeated from the schema or annotations.

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 destructive mutation with no output schema, the description covers side effects, concurrency requirements and auth scope well. The remaining gap is that it never says what comes back (e.g. the new commit sha), which matters for chaining follow-up calls.

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 only 17%, so the description must carry the load. It explains 'sha' (current blob sha, used for optimistic concurrency) and clarifies 'repo' as a scope, but 'message' (presumably the commit message), 'branch' and 'path' semantics are left entirely to inference from their names.

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 ('Delete a file from a branch') plus an implementation detail ('via git plumbing') and a REST equivalent, which is precise enough to act on. It does not explicitly name a sibling to contrast with (e.g. merjax_delete_branch for whole branches, merjax_write_file for overwrite), so differentiation is inferable rather than stated.

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?

Prerequisites are clear: the caller must already hold the current blob sha and the 'repo' scope, which implicitly tells the agent to read the file first and that it cannot delete blind. What's missing is a when-not-to-use clause, e.g. using merjax_apply_patch or merjax_atomic_multi_file_commit for multi-file changes.

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