github.add_issue_comment

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

With no annotations, the description carries the full burden of behavioral disclosure. It does reveal the dry_run behavior (preview without writing) which adds transparency. However, it does not explicitly state that posting a comment is a permanent write action, mention authentication requirements, or describe any side effects beyond the write itself.

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 concise sentences, front-loaded with the primary action and immediately followed by the most relevant behavioral nuance (dry_run). Every word earns its place with no redundancy.

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?

The tool has 5 parameters and an output schema, and no annotations. The description covers the core purpose and dry_run, but lacks explicit usage guidance, alternative distinctions, and deeper behavioral context such as auth or side effects. For a simple mutation tool this is adequate but not exceptionally complete.

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 0% (no parameter descriptions in the schema). The description adds meaning for dry_run ('preview without writing') and clarifies that 'issue_number' can refer to a PR thread. However, it does not explain body, owner, or repo, leaving the agent to infer their roles from standard GitHub knowledge.

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 uses a specific verb ('Post') and clearly identifies the resource ('a comment on an issue or PR thread'). It unambiguously distinguishes this tool from siblings like create_issue and get_issue by focusing on commenting on existing threads.

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 provides clear context that this tool is for posting comments on issue or PR threads, and it highlights the dry_run option as a preview mode. It does not explicitly name alternatives or exclusions, but the purpose is so specific that the intended usage is clear.

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