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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior, so the safety profile is covered. The description adds useful return-shape context unavailable elsewhere, notably that each account entry carries either the live link or the per-account error, and that the owner's note appears only if sent back.

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?

A single front-loaded sentence that names the resource, the key input, and the returned fields with zero filler. Every clause contributes information an agent cannot get from annotations alone.

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?

With no output schema, the description carries the burden of explaining return values and does so by enumerating fields and the conditional per-account error/note behavior. For a one-parameter read-only getter with full schema coverage and rich annotations, this is nearly complete; exact field formats or absence cases are not spelled out.

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 description coverage is 100%, and the schema already explains that the id comes from list_posts or create_post. The description repeats only 'by id' and adds no format or example detail beyond the schema, 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?

The description states a specific operation: retrieve a single post by id, and enumerates the content it returns (text, status, time, accounts, media, first comment, owner's note). This distinguishes it from list_posts and get_post_analytics by implication, though no sibling is named explicitly.

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?

There is no explicit guidance on when to use this tool versus alternatives such as list_posts or preview_post; the only routing hint, that the id comes from list_posts or create_post, lives in the schema rather than the description. Usage is only implied by the singular scope.

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