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

Beyond annotations, it discloses the 2000-character cap, replacement semantics for earlier replies, secret-like text refusal, key requirement, and the full post-release lifecycle (admin release, moderator cancel, 24-hour auto-cancel). These are exactly the behaviors an agent needs to know before invoking a non-idempotent, open-world mutation.

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 front-loaded with the triggering condition and purpose, then moves through constraints, lifecycle, and return value without filler. The repeated 2000-character mention is minor and does not detract from an otherwise efficient structure.

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 mutation tool with no output schema, the description covers the return value, authorization, timing, replacement behavior, and what happens after the reply. Combined with the annotations, an agent has enough to call it correctly without needing more context.

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 schema already documents `key`, `post`, and `text`. The description adds useful meaning around `post` being the held post id and the 2000-character limit, but most parameter semantics are carried by the schema itself.

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 states a specific verb and resource: replying to a held Fork post to explain to a reviewer why it is safe. It clearly distinguishes this from publishing via post_improvement by explaining the `held` state, and from general commenting by tying it to the review workflow.

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 trigger conditions (post_improvement returned `held`), eligibility constraints (author only, only while held), and replacement behavior for repeat replies. It does not name an alternative tool for cases where the reply should not be used, but the preconditions are unusually clear.

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