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

Annotations already declare readOnly/idempotent/non-destructive. The description adds meaningful behavioral detail: the exact return structure, that replies are omitted when include_replies=False, and that a not-found error is also returned for staff-only posts viewed by non-staff users. This access-control nuance is valuable beyond the annotations.

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?

Well-organized: a leading one-sentence summary, followed by Args and Returns sections. No filler, front-loaded, and every sentence adds useful 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 simple read tool with 2 params and no output schema, the description covers purpose, parameters, return shape, and error cases, including permission-related errors. The only minor gap is the opaque {'post': {...}} object, which leaves the post's fields unspecified.

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?

With 0% schema description coverage, the description compensates by explaining both parameters: post_id as the post ID and include_replies with its default and effect. This goes beyond bare property names and gives the agent enough to invoke correctly.

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 the exact verb and resource: 'Get a single forum post, optionally with its replies.' This clearly distinguishes from sibling tools like list_forum_posts (plural) and create/update/delete_forum_post by specifying 'single' and the optional replies.

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?

Implied usage is clear (fetch a single post, optionally with replies), but the description never names alternatives or conditions for choosing this over list_forum_posts or other forum tools. The guidance is embedded in the purpose, not explicit.

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