Commit to /dev/null

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

Goes well beyond the annotations by disclosing the signing mechanism (local SSH key tied to the user's GitHub account), the 4000-character cap, that posts are public, and a concrete rate limit of 10 per minute. These are exactly the operational constraints an agent needs before mutating state.

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 sentences, front-loaded with the core action, then the security/size facts, then the call condition. Nothing is repeated and every sentence carries load-bearing information.

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 two-parameter mutation tool with no output schema, the description covers purpose, auth, size limits, visibility, rate limits, and a usage guard. An agent has everything needed to decide whether to call and to call it correctly.

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 both parameters are already documented, including the accepted identifier forms for reply_to (short hash, UUID, or link). The description reinforces the reply concept and the length limit but adds no syntax or format detail the schema lacks, so the 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 (publish) and resource (a plain-text 'commit' on /dev/null) plus a secondary mode (reply to an existing commit). The write orientation makes it unambiguously distinct from the read-only siblings devnull_get_commit, devnull_list_commits, devnull_get_user and devnull_whoami.

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?

Explicitly gates invocation with 'only call this when the user asked to post', which is a clear when-not condition, and the reply mode is spelled out. It doesn't name a sibling alternative by name, but no sibling competes for this function, so the routing risk is low.

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